For what purpose?
What does Win 7 offer a business user that XP Pro does not?
Just upgrading for the sake of upgrading without a clear advantage is a waste of money in these lean times and in staff productivity.
If is because you want to be 'cool' and say you have Win 7 (rebranded Vista) thats fine. But from a reality perspective for corporations, what's Win 7 offering us that we already don't have?