As I understand it, the official word is that HTC will offer the JellyBean upgrade for AMAZE 4G, unless something changed a week ago. It's on the list for the JB upgrade, and HTC will follow-through with it. That OS upgrade is probably as far as it will go, however... but will you need more? Probably not. If I never saw JB on my phone it wouldn't kill me.
Put it this way, my new AMAZE (w/OEM ICS) just replaced a HTC MyTouch4G running Gingerbread. There is no comparison, IMHO. Will I need anything more out of an Android smartphone then what the AMAZE w/ICS offers? Probably not. Your requirements may differ. For me, I'll look to a tablet or laptop for those duties, as this is after all, a phone at heart. I can say that between the AMAZE phone and the ICS OS (in comparison to MT4G w/2.3.5), nearly most of my gripes about the old phone are gone.
I was also looking at the SGS2 as I just don't need a quad-core phone like the HTC ONE X or SGS3; but the Sammy's resolution isn't as good (or as bright) as the AMAZE display, and the little bit of extra screen the SGS2 has just doesn't make up for the lower res, IMHO. I want as crisp text and hi-res as possible, rather than extended black levels & contrast. This is a phone, not a home theater, where black levels & contrast would be a paramount concern of mine. Besides, though I have pretty large hands, the AMAZE is the perfect size, IMO. If I need a bigger screen, I want a tablet or laptop, not a bigger phone.
After having the AMAZE for about a month, I'm really liking it and, until I can move away from Android entirely, this will definitely do everything I want a smartphone to do.
Oh- I did upgrade the battery to a 1900 mAh unit. Much better life between charges, as I was getting about 6-7 hrs avg. before needing a charge. With the battery upgrade it's 15 hrs - >24 hrs, minimum, between charges. (depending on usage) Lengthy WIFI or GPS drains will intrude on that a bit. Overall, I take the phone off the charger when I get up, and usually don't recharge until bed, sometimes I still have between 40-50% charge leftover. Pretty cool. All of these phones with big displays really hit the battery hard if you aren't judicious.
Do I regret this acquisition over selecting the SGS2? Not one bit.
YMMV. Hope this helps.