Can I use Parallels Desktop on Zephyroth Leopard 10.5.2 AMD? Is it possible? Thanks.

yes.

Does Marvin's Utility now allow Parallels to run without having to resort to editing the app's plist string?

No it has nothing to do with Marvin's utility. Parallels just does a CPU check when it installs.

So its still a case of having to edit the plist?

yes, just to install it. You could probably use Pacifist to bypass this check, but it only takes a minute to edit the file anyways.

im using parallels on 10.5.1 it works fine for a single core cpu machine :) all i needed to do is modify a plist file so parallels would install

VMWare Fusion I see, also works. Do you think thats better than Parallels? I downloaded the trial version.

I like fusion a bit more personally, it seems to boot quicker and such.

you can experience the full potential of fusion only if you have qe/ci