Ok, so I'm a little late to the game on this one. The cf9 wish lists were going around a few months ago, but I'll chime in anyway.
I like that we're going to be seeing an expansion of cfscript to the point that you can write an entire cfc in script. A cfscript version of cfquery would be really nice. It'll be interesting to see how cfqueryparam gets handled because that tag is so important and so ugly.
The one thing I didn't see mentioned was support of xslt 2.0 and xpath 2.0. Both of them have been W3 recommandations for a while, but it looks like the development efforts of xalan have stalled. It doesn't look like anybody is working on it at all. Maybe cf9 can include the saxon 9b parser instead. You can get the saxon parser working in CF8, but it requires a little hacking. I always tend to shy away from those types of modifications simply becuase I tend to forget about them when the next CF version comes out and something invariably breaks.