Andy_Langton - 5:45 pm on Oct 1, 2012 (gmt 0)
I'd be a little cautious about doing this in the current Google climate.
One way of looking at it is that Google is going to evaluate each 301 you make - so each URL needs to correspond very closely with the content at the new location. The closer that match, the fewer problems you're likely to encounter.
The other factor is that redirecting multiple domains at once is also not without risk, because it corresponds with a 'buy domains to rank' strategy that Google is (perhaps understandably) suspicious of, or a symptom of a 'failed microsite' strategy where domains are created purely for link building and extra ranking opportunities.
I have made similar moves in the past without any undue headaches, but my opinion is that you should be more careful than might have been the case in the past.
It's absolutely critical that you get the redirects technically correct and the content corresponds as closely as possible.