The informed consensus on hit rating for rogues is this: trying to reach dual wield cap at 721 is retarded and will gimp your overall DPS. The recommended 'soft' cap for combat with 5/5 Precision is 315, which is the 'spell' cap for poisons. Beyond that you'll get higher DPS by concentrating on other stats like agility, ap, crit, haste, and expertise.
Remember you don't need to get all of these. Hit cap is not the fucking holy grail; you'll still be effective if you're a bit short. Just do your time in heroics for drops and rep and get appropriate gems and enchants. Check the auction house. Check the guild bank. Most of this stuff you can get with little or no effort and it will make a big difference in your damage output against raid trash and bosses.
Have Trollwoven (http://www.wowhead.com/?search=trollwoven) shoulders and belt made for the expertise until you get something better, since hit rating blues for those slots aren't as good.
Here's a filtered list of high lvl hit rating leather gear for rogues (and droods) minus PvP stuff to help grow out of your Eviscerator crap. Raid drops are included for reference.
http://www.wowhead.com/?items=4.2&filter=minle=200;ub=4;gm=3;gb=1;wt=119;wtv=100
Top picks for Naxx prep: * denotes gem slots
Feet:
(+48**) New 3.1 Pattern: Footpads of Silence (http://ptr.wowhead.com/?item=45099) - if you can afford it.
(+66) Boots of the Neverending Path (http://www.wowhead.com/?item=44297) - Argent exalted
(+38) Boots of the Whirling Mist (http://www.wowhead.com/?item=37666) - (H)HoS - Sjonnir
(+35) The Darkspeaker's Treads (http://www.wowhead.com/?item=44024) - IC group quest
Waist:
(+40**) New 3.1 Pattern: Death-warmed Belt (http://ptr.wowhead.com/?item=45098) - if you can afford it.
Legs:
(+52) Gored Hide Legguards (http://www.wowhead.com/?item=37644) - (H)Gundrak - Gal'darah
(+53) Azure Strappy Pants (http://www.wowhead.com/?item=44117) - Frenzyheart revered
(+45) Chain Gang Legguards (http://www.wowhead.com/?item=37890) - AH/BoE
Hands:
(+66) Gilt-Edged Leather Gauntlets (http://www.wowhead.com/?item=37409) - (H)UP - King Ymiron
(+33*) Heroes' Bonescythe Gauntlets (http://www.wowhead.com/?item=39560) - 60 Heroic badges
Chest:
(+51**) Crystal-Infused Tunic (http://www.wowhead.com/?item=37165) - (H)Nexus - Keristrasza
(+30***) Pattern: Carapace of Sun and Shadow (http://www.wowhead.com/?item=35218) - Leatherworkers (BC lvl!)
Wrist:
(+29) Drake-Champion's Bracers (http://www.wowhead.com/?item=37366) - AH/BoE
Cloak:
(+29) Cloak of the Gushing Wound (http://www.wowhead.com/?item=43406) - (H)VH - Erekem
Rings:
(+32) Surge Needle Ring (http://www.wowhead.com/?item=40474) - BoE (if you can afford it, current best in slot)
(+38*) Ring of Scarlet Shadows (http://www.wowhead.com/?item=43251) - JC/AH/BoE
Trinket:
(+55) Sphere of Red Dragon's Blood (http://www.wowhead.com/?item=37166) - (H)Nexus - Keristrasza
Enhancements: All of these are easily attainable and affordable with some effort. Again you don't need every one of them, and you'll want to get better DPS enchants as you get better gear.
(+8) Glinting Monarch Topaz (http://www.wowhead.com/?item=40044) for red or yellow sockets, get lots of these made.
(+8) Vivid Forest Emerald (http://www.wowhead.com/?item=40088) for blue sockets.
(+28 x2) Titanium Weapon Chain (http://www.wowhead.com/?item=41976) - Cheap and effective for blue weapons. Switch to Mongoose (http://www.wowhead.com/?item=22559) when you get better weps and gear.
(+16) Head - Arcanum of Ferocity (http://www.wowhead.com/?item=29192) - glyph from BC Cenarion Expedition revered.
(+12) Feet - Icewalker (http://www.wowhead.com/?spell=60623)
(+20) Hands - Precision (http://www.wowhead.com/?spell=44488)
Consumables:
(+45) Elixir of Accuracy (http://www.wowhead.com/?item=44325) - if you aren't using a Flask of Endless Rage (http://www.wowhead.com/?item=40084) for raids, save these for boss fights.
(+40) Snapper Extreme (http://www.wowhead.com/?item=42996) and Worg Tartare (http://www.wowhead.com/?item=44953) - good reasons to skill up your cooking and/or fishing, because these sell for ~80g/stack on AH.
Source: http://shadowpanther.net/enchantments-pve.htm
http://shadowpanther.net/consumables.htm
Hm, everything I've read seems to indicate you should go for the poison hit cap which is ~315, and shoot for 26 Expertise.
Bleh, I was probably looking at lvl 70 numbers mixed in with everything else. I googled and read through at least a couple dozen sources. Edited. But the soft cap concept is still valid - hit cap is not the fucking holy grail, and you'll still gimp your dps if you obsess on it.
From: http://foreveranoob.wordpress.com/2008/12/04/hit-rating-for-rogues-in-wrath/
The conversion from hit rating to hit % is now this: For a level 80 character, 32.77 hit rating = 1% reduction in chance to miss for melee combat.
Assuming that you have maxed your weapon skill at 400 when you get to level 80, then...
1. The first +hit milestone is to reduce your chance to miss (yellow damage) by 8%. That will mean that your special attacks never miss on raid bosses. To do that you need 262 hit rating. However, many (if not all) rogues will take 5/5 in Precision. If so, it reduces that required hit rating to 99. Easy enough. You'll get that much hit rating without even trying if you have decent gear.
2. Next is the Poison cap. This means that your poisons will never miss (be resisted). You need 17% for that. However, this uses the hit rating conversion for spells rather than melee. That conversion is 26.23 hit rating = 1% at level 80. So we would need 446 hit rating without Precision, or 315 with Precision.
3. The next one is to never miss with auto-attacks (white damage). You would need 27% for that, which is a whopping 885 hit rating if you have not taken any points in Precision. With the Precision talent factored in, it drops to a still-high value of 721. You could eat some Snapper Extreme to get 40 points toward that total, but you still aren't going to be hit-capped any time soon.