Waiting always seems smart, however while you wait you don't have a (new) computer.
If there is a feature that you are missing from the current Macbook pros, and that is expected to be part of the new MBPs, then it can make sense to wait.
Reasons to not wait:
- you have to put up with Windows for another 6 month
- there might be features of the new models you don't like
- there can always be delays
- the first version of a new product/design could be particularly buggy
your choice