Webkit-based canvas support in pyjamas desktop would allow developers using canvas apps to use pyjamas desktop in Ubuntu 10.10 & provide better support on all Windows OS's & Mac OSx.
Previously the main version of Pyjamas Desktop in Linux was based on XULRunner. Partial functionality was available on Mac OSX via Webkit and on Windows via MSHTML. Canvas support in Webkit was (and still is) unavailable, and I believe MSHTML canvas uses VML, which is pretty slow. Since then Ubuntu completely destroyed the ability to use XULRunner's hulahop, breaking Pyjamas Desktop and several other programs (last working version of XULRunner is 1.9.1 on Ubuntu 9.10), and while I'm not sure if other Linux distributions still run XULRunner-based Pyjamas Desktop, it seems that XULRunner-based PYJD is now obsolete, especially since Webkit version got a lot better, and faster than XULRunner.
Unfortunately, Webkit version does not currently support canvas. This is a big bummer as canvas is one of the main Flash-killer features of HTML5.
Create support for mobile platforms (iOS/android) to work with mouse inputs.
And a port of Tomas's A parser stuff to python, along-side fixing up that java2python project that uses ... what is it... not python-ply, the other one.
perhaps under the guise of adding that "dynamic decision stuff" for SVG Canvas.
Creating a web application framework on top of pyjs's ui and browser library for making application faster to create and run and looks beautiful. ( css theme, layout, event propogation, secure rpc, project organization, multiple app in one app etc )