I'm a 5'2" IT as well, and have also been shopping for a dress for summer wedding. I wish I had more great suggestions to share. I kind of got stuck on that Helmut Lang one we were all drooling over http://www.matchesfashion.com/product/193332# but it's way more than I wanted to spend. Plus it's, you know, white, and I'm not the bride at this wedding.
But here are some observations.
1. Bustiness can create a box-like, old school maternity-wear shape when a dress is too straight or trapeze-y, so look for some waist definition.
2. High necklines are overly enboobening, so look for a V.
3. Avoid spaghetti straps and look for something with wide straps (if you're going sleeveless) or even a cap sleeve. I know Angie feels those are often unflattering, but if they're not unflattering on your arms, I find they compliment the IT shape fairly well.
You're after something like this: http://www.ebay.com/itm/Helmut.....75316850?p or this http://www.ebay.com/itm/HELMUT.....0-/1311750 rather than something like this:
http://www.ebay.com/itm/Helmut.....5-/3710522
or this:
http://www.ebay.com/itm/NWT-39.....8143?pt=US
I seem to be in a Helmut Lang box at the moment, but you get the idea.
