What, northwind just isn't gonna do it for you?
(for those who aren't aware, northwind was the sample database Microsoft shipped with early versions of access and eventually SQL server)
Anyway, here's a biggety big data set you can play with:
http://www.clearbits.net/creators/146-stack-exchange-data-dump
Surely you are familiar with Stack Overflow and Stack Exchange. If not, they are question and answer sites. Users, vote counts (voting records are not in the data dump), comments, etc. It's a rather simple database, but it's got a lot of data, and you can probably do enough with it to de-crust your SQL skills.
It's all licensed cc-wiki, and is released 4 times a year now. There are dozens of sites in the network (programming, servers, bicycles, photography, cooking, etc) so there's a lot of data there - compressed it's just under 5GB.
Also, they have an open data explorer at
http://data.stackexchange.com/ which works against the live database. You can find all sorts of example queries and info about the structure there.
Also, keep in mind that microsoft does provide a number of sample databases beyond northwind, and they can all be found here:
http://sqlserversamples.codeplex.com/
Good luck, whatever happens! Every time I've been laid off it's always been an upward move, so I think you're right to think of this as a positive thing.