netmeg - 2:01 pm on Apr 23, 2012 (gmt 0)
I actually deal with this quite a bit - I have event sites that are specific to different locations, but some of the events (and the "maintenance" pages) are very similar; in other cases I have repeating events or events that span days or weeks on the same site.
For the most part, as long as the percentage of these is small, I don't really worry about it, and it hasn't seemed to have hurt me any. Note that in the case of products, I wouldn't want to be using a manufacturers description in this scenario.
For some of my longer pages that need to be published across several domains, I will either just put the page on one and link from the other sites, or I will only index the strongest page and noindex/follow the copies on other sites.
If the page really doesn't need to be in the index at all, I'll just noindex it across the board (search results pages, privacy policies, etc)
So far, I've never had problems with algo changes or pandas.