Using the MSS In a OS X Environment
A frequent question asked is how to use the MSS in an all-Mac environment. It's no problem and forum member, and Apple guru Abulia has written several key  posts on using Apple products and the MediaSmart Server.
When you unpack the MSS and set it up the MSS leases an IP address and looks for any computer running the MSS Console. In the past that would have been a problem with any Mac user but now days with virtualization software and Intel-based Macs able to run Windows native it's not a big deal.
MSS Setup With OS X -- Intel
If you have an Intel-based Mac made within the past few years you have many options available to you. Run Windows on your Mac via Boot Camp or run Windows virtualized in OS X. Both will allow you to install the MSS Console software to setup your MSS.
Boot Camp is available from Apple with the Leopard operating system. It does not include a license for Windows; you will have to provide that yourself. Once Boot Camp is setup you will reboot your Mac and hold down the Option key at startup. You will have a Windows partition to select and boot into.
Once in Windows, insert your MSS disk and install the MSS software. If you don't have the disk, you can download the MSS Console directly from the MSS if you know its IP address. Point Internet Explorer to \\serverIP:5050
This is the easier solution but more costly. Download Desktop or VMWare Fusion and install on your Mac. Both of these programs have trial versions. You will still need to provide your own Window's license, however. The plus side of running virtualized is that you can setup your MSS from within OS X without rebooting. Much less mess.
As with the Boot Camp version, install the MSS Console software to setup your MSS or point your Windows (not Safari!) web browser to the MSS, port 5050.
MSS Setup With OS X -- PowerPC
Unless you can borrow someone's Windows machine for setup you have only one option on an older Mac: VirtualPC software provided by Microsoft. It is a free download and no longer supported--and runs like a dog!--but it will run well enough for you to install Windows and get the MSS up and running. After you have the MSS configured you will no longer need to use VirtualPC and can use the Remote Desktop Connection (RDC) client below.
The good news is once you have your MSS configured via the Console you'll never have to use that again. Once setup you can now use Remote Desktop Connection to administer your MSS. This program provided by Microsoft runs on both PowerPC and Intel-based Macs. Make a note of the IP address of your MSS. In the connection field for RDC enter the IP followed by "/connect," like so.
That connects you to your MSS and into console (root) mode. This lets you administer your MSS from the Windows desktop without the annoying MSS Console. Install iTunes, manage your scripts, etc from here. If you need to get to the MSS Console, use the link right on your MSS desktop (within RDC).
Once you are done administering your MSS do not log out! Simply terminate the RDC connection, locking the console. Logging out will shut down iTunes and turn off your MSS streaming to your ATV!
The Q&A Section
Can I Use Time Machine With My MSS
Simple version: No, not currently.
Long version: It's a messy hack, but basically Time Machine doesn't like to play nice with SMB shares like the MSS. Even setting up a monolithic sparse image file eventually your Time Machine backup will corrupt. Time Machine does work over the network but only across AFP shares and the MSS doesn't support that natively. You could probably get it to work but it probably wouldn't place nice with the WHS file duplication system, thus defeating the purpose. Use a locally connected USB drive, Time Capsule, or a second drive in the case of a Mac Pro.
There is a software update coming to the MSS that will include an OS X "wrapper" front-end that will allow the MSS to be seen by Time Machine and backup to it. Because this wrapper must be installed in OS X to see the Time Machine content, you will be unable to restore from backup in the event of a boot drive failure. (Content is backed up; you cannot install OS X directly from the backup.)
Do I Have To Manage My MSS via The MSS Console?
No, that's a little secret that HP doesn't really want you to know. The MSS Console locks down the screen and prevents you from messing up a lot of things or doing exactly what we're doing, installing other applications like iTunes. You can manage the MSS just fine via RDC or Terminal Services, be it on a Mac or PC.
I Installed The MSS Console and My MSS Wants To Backup My Mac?
The MSS sees your Mac (via Boot Camp, Parallels, VMWare Fusion, or VirtualPC) as a PC and the default behavior of the MSS is to install the backup software utility and schedule backups. From the MSS Console goto the Backups tab and disable backups on your faux PC.