We've had our MBP for a year, set up with my Apple ID. Got an iPad recently and set up with another Apple ID. Would now like to sync the two and set up iCloud/PhotoStream. How to do since have two different Apple IDs?

Just out of curiosity, why did you elect to use a different id?. That seems to always make things difficult. If you have not had the pad for long, or have not bought a lot of stuff Nader the new id, you might want to think about erasing all content, turn off find my phone, wiping the pad and starting over.

You can sync 2 different ids ( at least move pictures, books and music back and forth) if you are syncing through I tunes on your computer, but I don't think you can cross feed I cloud streams.