Oh a pickle indeed.
Personally I love Nikons, however for my first DSLR I am a bit...stuck.
I did originally intend to get a D50 but they are now hard to find, the D40 is good but the lack of internal AF motor will be a pain later on. So the D80 was the next choice and I've used them a lot and I like them.
However....
D80 + 18-135mm standard kit lens = ~£700
Canon 400D + Canon 18-55 + Tamron 55-200mm + Centon Backpack = £600
I do love Nikons but is there a compelling reason to spend the £300 more on it? I'm not so sure anymore.