1) A really good list program, similar to ListPro for WM. I'm able to do a lot of my list stuff in ideaMatrix, but something more robust would be welcome.
2) Good document support (Word & Excel.) I haven't looked at the status of Docs To Go lately, so maybe that fits the bill...
3) Something that lets me zoom into a PDF without it getting all blurry. I put a PDF copy of my airline confirmation info into my 'Berry, but couldn't read it well enough to actually use it. Fortunately, I had also brought along a paper copy (because I'm just a little bit Type A.)
It's possible there are already apps to meet these needs and I just haven't found them yet.