We have several products which have a lot of shared code and which must be maintained several versions back.
To handle this we use a lot of Eclipse projects, some contai
Write a Hudson plugin which understands projectSet.psf's to derive a configuration and build it.
That seems like the winning answer to me.
I work with CruiseControl rather than Hudson but in my experience if you can create a plugin that solves your problem it will quickly payoff. And it is generally pretty easy to write a plugin that is custom fit for your solution as opposed to one that needs to work for everyone in a similar situation.