Questions about MacOS X Leapard

What happens when you try to use the new iChat features with someone who has the old version?

Can you have more than 4 spaces?

Does Time Machine back up the files in Windows under Boot Camp/Virtualization?

If you set up your time machine to work with your home networked drive, what happens when you are away from home?

Why the trend toward big blurry icons?

Recently I have upgraded various apps on my PC. And it seems like all the new versions use bigger, blurrier icons. The most recent was the huge new version of Adobe Acrobat Reader. Perhaps I should switch to a 3rd party reader.

Why not "No to all"

When I am copying stuff in Windows, and there are files with the same name already in that deirectory, Windows gives me the options "Yes", "Yes to all", and "No", but not "No to All". Seems like that is the option that would make the most sense in most circumstances and it is the only one missing!