Upload & Sell: Off
I've resisted the urge the to upgrade to Lion because of issues like this, which generally seem to be a low priority for Apple as photographers are not their main customer group. The Canon drivers for my 24-inch printer should have been updated by now (they were scheduled for November 2011) but it's been quite a while since I've had a chance to print anything, which certainly simplified matters for me
I think that in some cases the usual 8-bit printing works ok but if you want to benefit from the less common 16-bit printing then updated drivers are more critical. Sometimes there is a need to upgrade in a specific sequence to make things work (e.g. software before OS, or vice versa). Other times you just have to wait for Apple and the software vendor to see who comes out with the solution first. In the worst case there is no work around in the interim.
At least you're good to go now.