Yes it will. I run crysis on medium on my system and cryostasis on low. Both stay over 30 fps. I have an older radeon 3870 (a bit better than the 4670 and probably a bit worse than the 5650 when it comes out). Oh, and I play at 1920*1080 on everything (including crysis) except cryostasis.
I would personally recommend changing the CPU to the Athlon IIx4. As more and more games take advantage of more cores, this will help more than the L3 cache and high clock speed. (It helped me a lot in dragon age. I get 30fps while my friend with an identical system but with a dual core has to turn down settings).
If you want to keep your L3 cache, you could go for a phenom II x3. All 3 CPUs are around the same price (Athlon II x4 620, Phenom IIx2 and Phenom II x3)
I would also recommend 4GB of ram. My system is just barely passing with modern games that need more ram (I only have 2GB). Better to get 4GB of slower ram than 2GB of high speed ram.
You're cutting it kind of close with the 400W corsair PSU. Get a 500W corsair.
That was a big help to me i choose that best ans see that!
And as core unlocking success rates are high in 550be i would lyk to try that if luck favours than its a bang to bucks.
As i m low on budget that corshair 400cx isnt fine?
I will add that +2gb ddr3 later when i have something in my pocket.
I got it in a combo deal with my Phenom II x4 955 on dark friday it was on newegg.com both for $230
The original price was $119 but I got $10 in rebate, $55 at the discount for the combo.
You will have to get a better PSU, the minimum power requirement for a 5770 is 450w
You might want to take a look at a 500w 550w.
Take a look at this COOLER MASTER eXtreme Power Plus RS-500-PCAR (not very sure if cooler master make good psu's, but this have a good price now on newegg.com)
or this Thermaltake Purepower W0121RU 600W