IGN just did a bit on the games coming out in the next few months. Not all of them look great, but others may be day one purchases. Which ones look worthwhile? 
 
Day one purchases: 
Phantasy Star 0. A revolutionary handheld online multiplayer game
The Saboteur. Played at PAX. lots of fun, and lots of freedom regarding how to play. This one is good folks
Silent Hill: Shattered Memories. Looks like the best pure horror game since RE2
Sky Crawlers: Innocent Aces: Unique control scheme plus based on great movie and has gotten great reviews

Do want: 
 A boy and his Blob: 2D platforming goodness   
Brutal Legend: the demo at PAX was a good bit of fun, and the humor was top notch 
Demon's Souls: Looks fun
Resident Evil 5 PC: Technically I already own it, because I won it at a Capcom launch party in Seattle, then gave it to a friend

Could be good:   
Assassins Creed 2: The first one was fun but got stale. I want to continue the story, but the game needs to be good.
Dirt 2: Haven't tried many rally games  
Dragon Age Origins: Haven't seen much about it, but the hype makes it sound exciting 
Gran Turismo: Not a huge racing fan, but this does look nice.  
Half minute hero: The idea intrigues me, but I need to see some more info  
Halo 3 Odst: It 's halo, but i'm still willing to give it a chance
Persona: How much has it aged?
Rabbids Go Home. I need to see more gameplay. 
Resident Evil: The Darkside Chronicles. I really liked Umbrella Chronicles, and this should be more of the same.
Tatsunoko vs Capcom. I am looking forward to seeing who the extra characters are.   
Uncharted 2: I played it at PAX, and while the shooting elements seemed great, the acting was Crimson-Skies level corny and the climbing segments were more boring than similar bits in Assassins Creed

 
Don't want:  
Borderlands: Despite the new art style, this game does not interest me.   
Call of Duty Modern Warfare 2: The first one was a lot of fun, but shooters just aren't my thing
Dead Space Extraction. Played at PAX. it's lacking intensity, and the shooting wasn't particularly fun. 
 Drawn to Life: The Next Chapter. I'm not yet sold on the depth. 
Jak and Daxter: Don't hate me, but i've never cared for the series
Littlebigplanet: Were I working on this game, I would have removed some things in order to keep multiplayer 
Naruto Clash of Ninja Revolution 3: I've really enjoyed this series of fighting games despite lacking a lot of knowledge on the series, but the continuous roster adjustments (every year?) really force me to wait until they've shown every character. 
New Super Mario Bros Wii. Looks like a great party game, but i can't see the solo adventure being much fun. 
Spyborgs: I just got done playing Marvel Ultimate Alliance 1. didn't like it much. This doesn't even have marvel going for it. 
Zelda: Spirit Tracks: I've already got a DS Zelda. I don't need another..  

 
Giant duds: 
Teenage Mutant Ninja Turtles Smash Up. Played at PAX. it's lacking interesting attacks.  
 
No Idea: 
Ju-On: The grudge. I don't know much about the game other than the box art and source material 
 
I may have skipped a few, but in general the ones that aren't here I don't care about.