Emphasis on the first or second syllable? I get the impression that the latter is a British thing, but I might be wrong.
Weekend
Josh: Yes, in British English the stress is on the second syllable, [wik"End]. I don't know why Brennus thinks that this must be a recent development, or even that it must be an innovation. For all I know, [wik"End] might be the original pronunciation, and North American ["wikEnd] the innovation.
I was just speaking to an RP speaker earlier today, and I noticed that she said [wi:k"End]. I was wondering if perhaps the pronunciation of the word varies with social class or geography in the UK.
Interestingly, although the Cambridge Online Dictionary gives [wi:k"End] as the primary pronunciation (and this one has seemed to be predominant among the British people that I've heard), they do list ["wi:kEnd] as an alternative, without marking it as specifically American. So perhaps there is some variation in the UK as you suggest.