Not to confuse matters (which means I'm immediately going to confuse matters), but have you considered Enlightenment?
I liked the original ELive 1.0 LiveCD and they've updated now to 2.0.
Without knowing the error you're seeing I can't comment but it looks like the 2011 MBP AMD card is supported by X11, but it may just be that the distro you're trying isn't coping.
https://wiki.archlinux.org/index.php/MacBookPro8,1/8,2/8,3_(2011)#Video_and_screen
At worst it should be possible to boot with the VESA driver and at least get a functional environment, and then you can debug the graphics issue.
From what I can see, Ubuntu isn't the optimal choice (personally I run CentOS and RedHat but I'm in a production environment and need an enterprise ready distro) but it looks like these can be overcome based on this thread:
Arch and Elive Linux both seem to be getting thumbs up. If it was me, I would go here: http://www.elivecd.org
Otherwise, just wait for 64 bit support on OS X but you may be waiting a while.
As for the earlier comment about Linux only being free if your time has no value, I'm not sure what that says for Windows because I've spent so much time fixing that heap MS should really pay me to use it. That's why I use a Mac.
Good luck on your search. I try out 42 Linux distro's in my 13 years and like everyone of them except Elive. Since I hate/dislike Elive, maybe you should take a go at it. You might like Elive.
It's been years since I try out Elive. I might like it now, but I haven't try it out lately to see if I change my mind on this Linux distro.
There is also Macpup and Enlive which are based on Ubuntu or Debian.
To answer your question though, yes, Macbuntu seems to have stopped at 10.10 which means the software is mostly 2 years old. With linux Distros though, you can usually run a system update and bring all of your software up to date. (apt-get update && apt-get dist-upgrade type commands). With the changes in Ubuntu since 2010, the Macbuntu effort might be dead. The other two should work great. Both are designed for minimal resource use and should work well on a cheap PC.
I've never tried linux on a mac but support for most mac hardware is included in the kernel. The only problem is whether the distro you choose to liveboot includes a kernel that supports it.
I believe elivecd has mac support in the kernel. The stable version is quite old but it's just a live test right? You don't need to install the distro, you can run it in ram (it's lightweight). If you'd like to install a distro and test it for a while then I wouldn't recommend the same one (it's not faulty, but it's not something I'd personally use as an installation).
There you go: http://www.elivecd.org/
Yes. None of his code was GPL, especially since the GPL didn't even exist yet and he was writing about physical copies of paper punch tape.
The Elementary team is clearly wrong and are being roundly sanctioned by the open source community. I've never downloaded their code, compiled or otherwise, and over the years, have contributed to one similar open source project, the elive distribution, but that's because I used his software in a professional context and thought that it would be rude of me not to send some cash upstream. The fact that I am using free software, sending bug reports upstream, and putting my eyeballs on code every once in a while when I have some spare time and motivation, I consider myself more of a part-time field integration testing agent than a "consumer." I am now disinclined to ever look more into this project, and am glad that they are being taken to task for their arrogance.
eLive. It's Debian (squeeze I'm guessing) with E17, and it's pretty slick and comes with a boatload of drivers...although the developer wants a suggested donation for an installation key
If you're just looking to get acquainted with Linux, try a Live CD. Personally, I would point you to Ubuntu based on the community support, Fedora (Red Hat) if you'd like to see how the other half lives and if eye candy is your thing, try Enlightenment.
Now, Live CDs tend to be exceptionally slow (you're running the OS from a CD/DVD drive) but this way you can foll around and if you don't like it you simply reboot the computer and you're done with it.
>(hence the slogan From Freedom Came Elegance - it's a dig at some of the decisions Canonical have made over the years)
Really? I thought that was actually this guy's slogan, not Mint's. Am I mistaken?