Who knows, in a few years small groups of these engineers may be founding their own startups.
For example, I am part of this 8000, and I, along with many peers, were hired from HP to (at first) do the same job as before, but for GM. We had previously been contractors or part of HP Enterprise Services with GM as our customer. So, for a good number of these it wasn't a bunch of jobs being created but a simple insourcing shift.
It's been roughly two years since my transition over to a direct job and I've been happy with the choice to take the offer. There's nifty things happening here, way more flexibility and opportunity than before, and GM's a good company to work for.
ADDENDUM: I wouldn't consider myself a programmer; I'm more of a systems engineer / troubleshooter / sysadmin who writes small utility things as-needed.
Also, could have been wrapped up in all sorts of other agreements about termination of contract. This was probably a major deal for both companies.
I work in the GMIT Austin Innovation Center.
http://gmauthority.com/blog/2013/03/why-did-gm-choose-arizon...