Quoting my own response to a different thread...
Based on posts made in these forums some months ago (could it be almost a year?), the word seemed to be that a new version of PWS would have to wait until after Parallels Server as the overall plan was to move to a more modern, unified codebase based on the PD and PS code.
So, where do we stand... According to the Products page, Parallels Server for Mac is available for purchase. Parallels Server for Windows and Linux is still in Beta. This is interesting in that one would think a single product family based on a single unified codebase should be at more or less the same level of readiness. Moreover, PS/Mac even includes features that must have required some significant Mac-specific development such as the ability to virtualize Mac OS X Server.
I'm inclined to infer that one or more of several things must be taking place:
1) Parallels is, quite simply, throwing the bulk of its efforts at the Mac, recognizing that it is the only platform on which it has any significant advantage over the competition (nobody else has a server product for the Mac and PD still has some feature advantages over Fusion and VirtualBox).
2) Parallels is finding Linux too hard to keep up with. As a Linux user, I cringe at this thought, but it's interesting to note that ever couple of kernel releases seems to require a new/different patch to allow the kernel modules to compile. (For a while, users of VMWare products on Linux had to rely on unsupported community patches to compile there kernel modules, also.) The patch for 2.6.25 also requires a kernel rebuild with specific options set, moving the problem out of the realm of the casual user who just wants to run whatever kernel came with the disto.
3) Parallels is still working on (looking for?) the killer feature for a Windows/Linux product to make it more than a "too little, too late" or "been there, done that" upgrade. This is the correlary to inference #1. Between VMWare Workstation 6.5 and VirtualBox 2.x, all of Parallels early wins on the Mac (3-D, seamless windows) have been done. VirtualBox also takes away the possibility of releasing an inferior product and trying to win on price (arguably, the strategy that PWS was using in the first place). Conversely, if they do have such a feature, this might explain why there has been no formal product announcement, no beta, etc. as the plan would be to simultaneously announce and release, giving the competition no time to react.
Personally, I don't think we'll hear of a release until after (or simultaneously with) the PS for Win/Lin release.
What I can't fathom is what Parallels will do to build a Windows/Linux user base. As it is, the delays and inattention have damaged the trust, if not driven away, many early users. Just winning them back is going to be challenge enough and while the free upgrade may get them to come back and look, there is going to have to be some kind of public commitment to continued support in order to get them to stay.
Honestly, I just wish someone in some authority at Parallels would just come out on the blog and say "Look, here is where we are WRT Linux and Windows. Here is where we are trying to get to. And here is what's keeping us from getting there."