Whatever you do, do not even attempt to "migrate" or clone your CS3 installation from your Power Mac to your Mac Pro.
Just use your CS3 install/upgrade media and any previous serial number it may prompt you for. Adobe upgrades are all full installers, they'll just prompt you for a previous serial number if needed.
At this point, I believe know that CS3 still qualifies for an upgrade to CS5 for a mere $199. In a few weeks or a couple of months it won't qualify for an upgrade to anything. CS5 is a 64-bit application of which your new Mac Pro can take full advantage. It's a no-brainer. Upgrade ASAP.
Just to "fine tune" the advice from Ehemaliger regarding the upgrade from CS3 to CS5... CS6 will be announced in April and will be available in May to purchase.
The period between the official announcement and being able to actually buy the product is called the "Grace Period." If you upgrade from CS3 to CS5 during those few short weeks, you will get CS6 free-of-charge once it's available, although you will have to contact Adobe's Customer Service people with proof of purchase to do so.
Moving from CS3 to CS5 during the "grace period," and then getting CS6 for free, would be the most cost effective way of upgrading, although Adobe are giving users of CS3 and CS4 the option of waiting 'til the end of the year, 12/31/12, to upgrade directly to CS6 if they so choose. The trick here is that nobody knows how much that upgrade will cost! LOL!
Beyond that we will no longer be allowed to fall behind, and will have to upgrade on every full release whether we want to or not!
But once again as Ehemaliger said, CS5 is 64 Bit so you'll be able to take full advantage of all the RAM you install in the system, so upgrading really is a no-brainer!
Hello, Zone. CS3 is an universal binary, it means that you can install it on your new Mac that has Lion. Remember to run all the updates to have the latest patches and Camera Raw version.
If you purchase an update to CS5 or CS6, be aware that a previous install is not needed on that machine, a serial number will be enough.