Tiny Core Linux 4.7 overhauls the OnDemand system
h-online.com
h-online.com
It seems to me there are huge advantages to doing that because if your run mamp on your mac for web development your quickly bump into problems like installing memcached or non-mac services. You also get more experienced with linux..
There actually already is something available for this called TurnKey Linux (http://www.turnkeylinux.org/).
A quick hint, if you do develop sites locally on your mac and get annoyed with Mac's weird dns lookup (.local, skipping the hosts file if it's not in a specific format.. etc) check out Dnsmasq (http://en.wikipedia.org/wiki/Dnsmasq). You can install it on your mac using port.
Biggest beef with VMWare Fusion is that it doesn't support Workstation teams...
For example, I have a Mint appliance that's about two gigs, while my Tinycore version is 200 megs. It's pretty nice to have that fallback when you have to retrieve it over the internet.