[OJsakila]

ok first you will not break your phone as long as you continue to be an AT&T customer. It is those that have their phone unlocked to another carrier that have reason to worry. Most apps are cool and neato but alot of folks seem to think they are useless and increase the phone's instability.
I, however, have my phone modded tonthe hilt and love it. Sometimes some new apps DONT work and I have to deal with it. All that means is that I have to remove the app and in the worst case I might have to restore and start all over. Once you get the hang of it, to restore and then jailbreak the phone might take an hour at best behind the computer. This iPhone is quite durable and resilliant and I would have ZERO fear of modifying your phone as long as you are with AT&T on a legit contract. Its fun and In a short time you'll come to know your phone like the back of your hand...
The "apps" you speak of that come out in Feb is actually the ability for those that have the know-how to develop applications... That could be pay only.
do some research and feel free to modify.
and yes a restore erases your content but you just put it back on. No biggie. You shouldn't have anything on the phone that you don't have a backup of somewhere else.