I don't have 2K9 so I can't do any work with it myself (and thus don't have any first hand experience doing what you're suggesting) but I'd say you can take some textures and use them for NBA Live 08 patches. That's probably about it though.
just to confirm, what andrew said is true. We can extract textures and import into Live if we wanted to, but dont think that using 2k9 stuff will allow us to have moving jerseys or anything of that nature