Got one of the last Mac Pro 5,1 (mid 2010) models from B&H Photo they had in stock that specifically came with Snow Leopard. I really didn't have a reason to upgrade from my 2008 Mac Pro yet, but wanted to get as new of a piece of hardware that I could that still ran SL. Bought it about 2 weeks after Lion's release.
I'm currently keeping it at SL for various reasons. For example with SL, it wasn't until 10.6.3 that it stable enough to use for prepress production work. By then, Apple had finally worked out all of the worst font bugs. They couldn't bring the old code forward anymore and had to rewrite the font engine from scratch for SL. So in a like manner, I'm still kind of waiting for Mountain Lion to settle. It actually looks pretty good now, I've just been to busy (and lazy) to start installing all of my software onto the test partition ML is on.
Most importantly though, is that I have two currently irreplaceable pieces of software that require Rosetta. One is Monaco Profiler. I do have i1 Profiler, but it lacks two extremely important functions Monaco Profiler has. One is the ability to make scanner profiles. The other is a true profile editor. i1 Profiler has an iterative profiling function, but all it's good for is tweaking prints to match screen color closer after you make the original printer profile you're working on. Nice I suppose, but a useless way to tweak CMYK profiles for making contract proofs in the printing industry. Your objective is to match the color of another printing device (a professional printing press normally), not your monitor. I can create the initial press profile in i1 Profiler, but if it needs editing, I have to do that in Monaco Profiler. Lots of folks have told X-Rite we NEED these functions. They recognize that, and users on our end also realize i1 Profiler is a 1.0 product and needs a bit of time to mature. Hopefully, I won't need Monaco Profiler anymore when we see version 2 of i1 Profiler. That'll be one PPC software down.
The other is our scanners. We have two Eversmart Supremes. First designed and made by Scitex (an Israeli company), later owned by Creo, and then Kodak. The software engineers always did as little as possible to update the software for OS X. The last release was for Snow Leopard where a few items had to be Intel native for it to work, but the bulk of the interface is still PPC code only. Kodak closed down the scanner division, sold off all of the hardware in the Israel plant and bulldozed the building. This is very proprietary software and hardware, which were designed together. There is no third party software to drive these scanners. There's also no other flat bed scanner that even comes close to the quality of these devices. They're as close to the output of a true PMT (photomultiplier tubes) drum scanner you can get in a CCD scanner. Unless someone else manages to finagle the source code out of Kodak for these scanners and finishes porting the rest of the code to native Intel, it's going to be forever stuck at Snow Leopard as the newest version of the Mac OS you can run it on.
It also doesn't work in a VM. I have Snow Leopard Server and installed it in a copy of Parallels, then the scanner software. It runs, but it can't see the scanner from within a VM since it can only find the hardware on a FireWire connection, and there is no VM software that supports FireWire port linking. That's another item many people are ragging on Parallels and VMWare for. Why isn't there FireWire support? If it had that, I could keep using the scanners for years without having to keep an old Mac running just for the scanners. FireWire ports may disappear from Macs fairly soon, but Thunderbolt is directly compatible with FireWire. With a simple adaptor, you can plug a FireWire device into a Thunderbolt port. So even that would work if the VM vendors would at least support Thunderbolt port linking.
So for now, having Macs that can boot to Snow Leopard are a must for us. (Hmm, that response became rather wordy. 😉 )