Why do people keep posting these threads... every day....
Ok, look. You even said so yourself a new iphone is probably coming out in June (or July). That is most likely true. Judge for yourself. Nobody knows how great the new iphone will be. So are you willing to WAIT 5 MONTHS to get an iphone or just go with the 3GS (a perfectly good iphone) now. You need to make the best decision for YOUR own needs.
It doesn't matter what I would do or what HE would do, or SHE would do... it's what you need.
Think of it this way. if you buy now, sure you will miss out on this 4th gen iPhone, but you will be able to upgrade right around when the 5th gen comes out. BUT if you wait till June/July you won't be able to purchase the 5th gen with your upgrade till like Dec/Jan.. putting you in this exact same predicament of buying or waiting. It's a vicious cycle. Decide what's best for you and you won't be disappointed 🙂