If your going to get a new console, I strongly suggest on getting an XBOX 360 Slim. Since I have both consoles, I think I should tell you why to get an XBOX 360. Reasons why:
*You already experienced what PS3 had to offer.
*XBOX 360 has better graphics, due to it`s PC-Like hardware, with HDMI, the Graphics look even MORE stunning.
*In my opinion, XBOX 360 Slim looks better than the new PS3 Slim.
*XBOX has a better Network than PS3 (XBOX Live), but it`s gonna cost you $60 a year.
*Red Ring of Death is extremely rare. XBOX 360 has become a hardy console, with only a 5% failure rate.
*I think it is false that XBOX scratches your disc, once, I took my XBOX from my living room to my bedroom (the second floor in my house, so I had to climb stairs) with my BF3 disc in the console, and it did not come out scratched.
In my opinion, since you already had a PS3, you should try out the XBOX. But, if you wanna save yourself money by not buying all the games again, get the PS3. You can`t go wrong either way. Also, there is not conformation by Microsoft about an "XBOX 720" and I think it will still be around 4-5 years before the next generation consoles come out. Hope I helped.
Expirience with BOTH PS3 Slim and XBOX 360 Slim.