Hi Angie, I had trouble deciding too. The reason I didn't go with the D3100 is that I needed a camera in early September, and it wasn't out. Instead, I bought the Sony Nex-5. I really really like it. I bought it with the understanding from the vendor, that if I didn't like it, when the D3100 came out, I could exchange it, with no restocking fee within 30 days. Well, I decided to keep it

I really like it, it's an easy to use camera. It takes great tank shots, and it is just as easy as any P&S... Granted, it's not a true DSLR it's a micro 4 thirds or whatever.... It's smallish, and it does have interchangable lenses. The negatives? I bought the kit with the 15-55mm lens, and it has met my needs well. I also ordered the 16mm, but it's STILL on back order!!!!!! Also, Sony has announced a 18-200mm lens, but it's out of stock everywhere, and it's $700!! You can buy an adapter to use lots of other lenses, but, you loose alot of the auto focusing, and intelligent settings.
If I had it to do over.... I'd still have gotten the NEX-5
I like the portability!