It took me several days of coding and tweaking, but I finally completed creating a new skin for my blogger blog (http://EnvironmentalChemistry.blogspot.com) so that my blog looks like my main environmental chemistry site. That was really challenging. I'll probably never get it to validate to W3C specifications, but it does display correctly in Firefox, Opera, IE6 & IE7, so I figure I'm pretty safe.
Overall the new Blogger development tools are pretty cool, but I would have liked more control over some things. Better documentation would have been really helpful.
If anyone is going to attempt to build their own skin for Blogger, I would really advise to make sure that you have upgraded your templates to the new Blogger first. Yes you will lose your old modifications but working with the new template design tools is really critical.