I'm still debating a bit on what to do myself since I'm inside 30 days of having my Evo LTE (currently on day 5... lol)
After having my Evo for a little less than a week, I'm enjoying the phone. I have no real issues with it. I don't know if the S3 is more "future-proof" because of the extra gig of RAM. That's really the only thing that kinda bugs me, even tho I don't notice the whole multitasking thing on the phone much. I've noticed it reloading a couple of things on occasion, but if I didn't read this forum it probably wouldn't bother me
The reasons I don't wanna get the Samsung is because of the Epic I had before. It was solid a lot of the time, but the updates that came out seemed to introduce more bugs. A good phone that started having more issues, and after 3 replacements I was ready for something else. I don't want another Samsung to be good then get all weird a year in. And I'm not into rooting & ROMing so I don't consider those options.
I guess all I can do is see the S3 when it comes out and compare. If there's no sale on it, I then have to decide if it's worth paying $40 for it over what I got the Evo for.
Ahhh..... analysis paralysis at it's best!