These days, any decent Windows desktop application must perform well and look good under the following conditions:

1. XP and Vista and Windows 7.
2. 32 bit and 64 bit.
3. With and without Themes.
4. With and without Aero.
5. At 96 and 120 and perhaps custom DPIs.
6. One or more monitors (screens).
7. Each OS has its own preferred font.

Oh my! What is a lowly little Windows desktop application developer to do? :(

I'm hoping to get a thread started with suggestions on how to deal with this GUI dilemma.

First off, I'm on Delphi 7.
a) Does Delphi 2010 bring anything new to the table to help with this situation?
b) Should we pick an aftermarket component suite and rely on them to solve all these problems?
c) Should we go with an aftermarket skinning engine?
d) Perhaps a more HTML-type GUI is the way to go. Can we make a relatively complex GUI app with HTML that doesn't require using a browser? (prefer to keep it form based)
e) Should we just knuckle down and code through each one of these scenarios and quit bitching about it?
f) And finally, how in the world are we supposed to test all these conditions?