Even 3.3 megapixel is more than enough for 5x7. You can get pretty good-looking 8x10 prints out of 3.3 if you don't have to crop. 5 is probably more than enough for almost any non-pro.
For my money, I would want something with more than 3.1 optical zoom. But YMMV. Also the range of apertures looks kind of fishy.... if f/2.8 to f/4.9 is accurate, that doesn't seem like much, and might limit some of your focusing option in some situations.
I'd suggest a trip to
www.dpreview.com.