i'm dual booting vista and intrepid ibex (ubuntu 8.10) on my dell inspiron 1525. works well. i've found ubuntu can be a complete replacement for vista these days. there's plenty of software available to replace what you're doing in windows. and it does read my ntfs partitions nicely. i don't have to copy my media files over to the linux partition to play them. very nice. i've even found the driver for the on-board wi-fi chip in ubuntu seems to use the hardware better. i just barely accessed an open wi-fi connection near where i work. i rebooted into ubuntu and the signal strength was quite a bit higher giving me a much more consistent connection. and that's from the same desk.
the only glitch i ran into was the hdmi driver. video on the tv and the monitor gets all buggy and stuttery when i try to watch movies on my tv through hdmi. i didn't investigate this at all and it may have been a simple fix. i didn't care enough.
other than that it's a short and shallow learning curve to switch. i say that with some experience. starting with red hat 6.1 right through to fedora core 4 (i skipped 3 for some reason), debian a couple of times, gentoo once, suse once, mandrake (i triple booted mandrake win 2k and red hat 7.x for awhile). kde gnome and enlightenment. all the browsers. all the email clients. chat, irc, ftp, text editors... i've tried all kinds of stuff as a user, not a geek. very rarely did i open a terminal and start typing. admittedly sometimes it's easier to but i didn't like doing it. mind you back in the day you didn't have a choice. getting X to run on slackware was frustrating.
installing and using ubuntu is very easy. they've come a long way.