As a developer I’m really happy to hear about this. Being able to build the tools to build the end result always feels great. 
I’m assuming that eventually Easel will have a published API we can hang apps from?
As for apps I would like to see?
- V-Carving (and the related engraving side)
- Another vote for the gears (I love http://geargenerator.com/)
- And a similar to gears, a “digital joints” app that allows addition of carvable joints to projects for things like box making. see: http://www.flexiblestream.org/project/50-digital-wood-joints (and more on the subject: http://makezine.com/2012/04/13/cnc-panel-joinery-notebook/)
- Some form of measuring tool that allows accurate placement of features and accurate sizing of said features.
This is exciting news, I am really glad I took the leap to get an X-Carve, it seems the whole ecosystem gets better and more exciting everyday.
Cheers
Ian