Which OSI license is best for NetDirector?

I need help figuring out which license to move NetDirector to. Right now, it's licensed under a modified MPL with attribution clause. I think I want to keep attribution, which would seem to rule out GPL and limit me to CPAL, or the newly approved MS-PL or MS-RL. You can see these at http://opensource.org/licenses/alphabetical

But, I also observe that many commercial open source vendors have embraced GPL, both versions 2&3, notably SugarCRM, Zenoss, Red Hat...

Do I need attribution? Bear in mind that, unlike the above-mentioned vendors, I am not VC-backed. I think this makes attribution more important to me - but maybe not.

Thanks!

Update - November 12, 2007

I'm pretty much settled on moving everything that's out there today in the comunity (all the stuff that can be downloaded from SourceForge) to GPLv2. Maybe someday there will be "Enterprise" editions of NetDirector that will have some other license, but I think GPLv2 is the ay to go.

thanks to everyone who chimed in with thoughts - I appreciate it!