Changed my blog template by uploading a non-standard template from Mashable.com. Upload was ok but the new template wiped out a few of the things I use such as my Blog Archive gadget and my top navigation bar. It also added in an undefined date element to the posts which i dont know how to fix. The template doesnt resize to fit the screen either. I also noticed a lot of comments and notes about compatability problems when investigating.

I think the range of different designs that are available are great but when you move beyond the approved designs you are likely to have to spend some time cleaning up the design. The incompatability and usability of non-standard designs is a bit of a worry also.