I love Jason Langridge's WebLog - MR Mobile!.  He says

“Well it had to start.. after we delivered Powerpoint Mobile in Windows Mobile 5.0 many customers are now asking me for ... Microsoft Project, Microsoft Visio and Infopath mobile versions...”

I would agree with Visio & Project for sure.  I would really like graphic drawing program like Pocket Artist.  My kids would love to draw with this!