Can I transfer my PC characters to my Mac?

I was hopeful that I'd be able to download and boot up Borderlands 2 on my mac this morning to the grand sight of all the characters I'd created on the PC version happily waiting for me. Unfortunately, that was not the case.

Edit: the offical word from Aspyr is that steam cloud sync between Mac and PC will not occur: The Steam Clouds are separate since the PC and Mac will be out of sync as far as versions are concerned.

So, given that this doesn't happen automatically, is there a way I can copy some files from my PC (bootcamp) to my mac and keep my character progress? It's not something I want to do more than once.

Yes, you can. I have my characters syncing between my Mac and PC.

In order to sync your files you need to copy all the save files from this location in Windows:

C:\Users\MYNAME\Documents\My Games/Borderlands 2\WillowGame\SaveData\76561197975478513\

To this location in OS X

Users/MYNAME/Library/Application Support/Borderlands 2/WillowGame/SaveData/76561197975478513/

Note: the folder /76561197975478513/ may be named differently on your machine. If the Library folder is hidden in OS X, go up to Go in the menu bar, hold alt/option and Library should appear. Alternatively, click on Go to Folder and paste in the following:

~/Library/Application Support/Borderlands 2/WillowGame/SaveData

It does work, moving save file to and from mac and PC. Your save file on the mac may be in the user's library folder in application support not preferences as previously stated.

The mac saves are, by default:

'Users -> %username% -> Library -> Preferences -> Feral Interactive -> Borderlands -> SaveData'

and the windows saves are, by default:

C:\Users\%USERNAME%\Documents\My Games\Borderlands 2\WillowGame\SaveData\(Random Numbers)

(in both cases, %username% should be replaced with your user name).

I don't know if they are compatible between mac and windows versions (I doubt it, even if they use the same naming scheme), but it may be as simple as copying the windows saves and placing them in the mac folder. If it doesn't work, you can simply remove them.