Not being biased - but i know canon and have canon - so nothing against Nikon - great Kit I just dont know it very well, and would recommend you have a look at the D70
http://www.dpforums.com/forum/showthread.php?p=11642#post11642
just not with selection of lenses avalible.
well that may take some money - you have a range on the camera of 38-210mm 35mm equivalent with the .5 and 3x I guess that gives you around 19 - 630mm in 35mm terms. - remember thats is 35mm and the 20D/350D/300d has a crop factor of 1.6 and the nikon has a crop factor of 1.5 - so a 19mm 35mm lens on those camera's will give a field of view of 19x1.6 on canon and 19x1.5 on nikon
so you are looking at 10mm to get the wide angle you may be used to.
and if you want high quality from the pictures you will be looking at "L" glass from canon.
also at the 35mm end you have an aperture of F2.8 - but i think its F8 at the 210mm end - so have a look at the canon lenses you fancy and price.
theres a great canon forum here
http://photography-on-the.net/forum/usercp.php? {hope members here dont object to posting this forum} which has loads of lens advice
if you go for the 20D as thats has a lot of features so you wont be in danger of growing out of
then the lenses look at price of L glass the 17-40mm gets great reviews
the kit lens that comes with the camera has a few bad remarks on quality.
but you are looking at 1000's ££££££££'s
have a look at this website for sample pictures
http://www.steves-digicams.com/default.htm and they have your camera there too so you can compare sample pictures from your camera with others