Zen Touch supports MTP with the latest firmware update. As far as I know it DOES NOT support MTP (i.e. Napster-to-go) out of the box.
I have the Zen Xtra (predecessor to the Zen Touch) 40gb version and have noticed that my player both slowed down and lost some capacity with the firmware update to MTP.
As far as Creative mp3 players go (my wife has a 4gb micro and loves it!), I have to say that hardware-wise, they are great. However, the Creative software and support blows! It took them a year and a half to get this MTP firmware rolled out for the Touch and Xtra, although they were selling them a year ago at Best Buy as MTP-compatible.
Unless you absolutely have to have the touch control (which I have to admit is more convenient) buy an Xtra, as they are virtually the same, software-wise, as the Touch. You can get a 60gb Xtra for the price of a 40gb Touch (~$200-220)
I bought Creative as they seem to offer the most gb for the dollar, generally have great reviews, and outdo the rest of the competition (in my opinion) with the inclusion of EAX.
The early versions of the Xtra were also plagued with a headphone jack problem that ironically occured 4-5 months after purchase (Creative's warranty is only 90 days) that left many users with a non-functional unit, as Creative charged ~$150 to fix it out of warranty. The problem was corrected, and fixed versions were quickly slipstreamed into circulation. Where I'm going with this is-- if there is an ongoing problem with headphone jacks with the Micro, then it's probably the same situation as with the early Xtras. Fortunately, there was a complicated, but very do-able home remedy.
Whether you buy a Touch, Xtra, or Micro, I would definitely recommend Red Chair Software's Notmad Explorer. It's a one-time fee of $25, and really performs. The Mediasource software that comes with the Zen players is HORRIBLE. I also have to point out, that although I haven't used it much, Windows Media Player 10 also seems to work very well.
Notmad Explorer allows you to use your Zen player as an external HDD, however the PC you are using to access it as an external HDD must have either Notmad Explorer, or Creative's Nomad Explorer installed. This is something to consider when you are "stealing" your friends' music.
Last, but not least, I've have had extensive problems transfering music downloaded via Napster-to-Go to my Xtra using the Napster software. A quick workaround that works great for me is to use WMP 10. Although it works great for my non-DRM mp3 and WMA files, I haven't been able to get Notmad Explorer to transmit those N-T-G DRM files.
The Xtra has a removable battery made by Motorola, my battery from my phone ALMOST fits (right size, just incorrect connectors). This leads me to think that there may be some phones out there that you can swap batteries with the Xtra. The voltage/amps/watts, all match up. I have no idea why the Touch wouldn't have a removable battery, as it's essentially Xtra rev. III, but hey, could be.
This is a lengthy post, but I hope it answers any questions you have. Creative's players are great for that-- mp3 players. I have had mine hooked up to my truck's cd-player via a mini-stereo cable for over a year now and have had minimal problems. I really haven't tried to use it as an external HDD, as I've already maxed out the 40gb capacity (my collection is sitting at 50gb right now... :-( ), so I really don't have room to mess around with that. If that's a big deal to you (external HDD) then rethink what you are buying. Otherwise, just get on of those 512 or 1gb jump drives that are always on sale after rebate at Compusa to "steal" your buddy's songs, and use your Zen to listen to them.