If it wasn't for those pesky kids...
... we'd be a windows free household too.
However....
1) Still no Adobe Shockwave support
"Dad, why can't I run those games on miniclip.com that all my mates say are great"
2) Limited MSN support
"Dad, I know I can chat to my mates on pidgin, but why can't I see their webcam / nudges / winks / smiley central stuff"
These two things might sound trivial to tech-savvy adults, but they're what most "normal" kids use PCs for - that and playing non-flash games, though thankfully I've convinced them that games consoles are the best way to play games ;o)
Yes, I know I can install the Windows version of Firefox with wine and work round point 1, but I've not found a solution for point 2 yet - windows live messenger thingy won't install with wine. Much easier for me to just leave them on XP and use an Acronis image of the windows primary partition to restore when (inevitably) the XP OS gets virus infected / corrupted / degenerates.
IMHO, PC vendors should be legally obliged to supply their full range of hardware without ANY pre-installed OS, priced at the same level as the systems with a bundled OS less the cost of the OEM OS license.
As user friendly as Ubuntu 7.10 is, running Linux is still a significant compromise while ever 99.999% of the population are running windows. If Linus Torvalds had chosen to develop an open source version of windows rather than unix, we might have gotten somewhere...