jsheirer,
Your right, the dialog box is not modal in 10.2.2. However, the pythonaddins.GPToolDialog() bug is back (see NIM-089253). I had no problem with this in bug in 10.2.1, but this is obviously a serious problem. I now have to roll back to 10.2.1 because of this. I can go on about the problems this causes, but I will save it for the bug report.