If you haven't done so already - get a copy of Powertab now!
Well, it was fun meeting him and discuss some of the features I'm missing. On is -
- dir $folder\[tab] should expand into dir $folder\file
An I gave my regards for PowerTab as such and the new constructor feature - try it yourself -
Anyway, the PowerShell v2 CTP enables him to do a full tokenizing of the command line, so even better intelligence will be possible.