The MacBook Pro has already been updated with the new components that people are waiting for in the MacBook.
Nothing new is expected in the MBP line until new Penryn chips, currently expected in January (or so).
So, in 3 months or so you could expect a somewhat better MBP.
As always, my advice is
"If you need it now, buy it. If you can wait, wait.
There will always be something better coming - so don't be paralyzed for fear of your machine becoming obsolete. It will become obsolete - get over it."
3 months