oh boy, did you open a can of worms!!!!
It's commonly done (called pitching on the cake) and we've had some boisterous discussions on this practice lately.
I'll find a few links to show you what I mean. Here's one: http://www.homebrewtalk.com/f163/why...t-cake-166221/
and of course the "related threads" at the bottom of this page.
I have done it in the past, and it worked well. I followed the practice of lower OG beer to high OG beer, as was recommended at that time. Lately, I've been practicing yeast washing and that seems to give better and more predictable results.