Desktop Android is not well known yet but likely will have a lot in common with the cell phone version, just be more robust and capable of doing more Windows-like things. It is also expected to boot incredibly fast and come with a rich Application Store.
Chrome, the Google Browser, is being positioned to take the value out of Windows through Cloud-based applications and, if successful, virtually eliminate the migration cost over time. Desktop Android is a precursor to a Cloud-based future .
Both offerings will bring with them a high degree of quality control, which could exceed Apple's and, because both will be hardware independent, both will gain economies of scale that Apple's hardware based model just can't match. This will be their strength and their weakness.
The weakness is they will have a harder time assuring the overall quality of the solution than Apple does. But both seem aware of the quality mess that surrounds Windows and are working to overcome it with their platforms by doing better job of assuring third party applications and drivers in-house.
Desktop Linux Following Desktop UNIX
Desktop UNIX never made it as UNIX but has been surprisingly successful as the MacOS. Yet unfortunately the idea of software that could both challenge Microsoft and be free is simply not reasonable.
The resounding lesson that many don't seem to learn is that if you want to be successful on the desktop you have to provide a solution that users, not coders, get excited about and one is not the same as the other.
Both Apple and Microsoft learned that lesson early on and now two other companies, Google and Phoenix Technology, plan to find a middle ground between Apple, Linux, and Microsoft in the hope they can outdo Apple and become a real challenger to Windows either initially as an enhancement (Hyperspace) or a replacement (Desktop Android). In 2009 we'll find out if either has the right stuff and whether Windows 7 will be up to the competition.
Windows 7 has its coming out party in a couple weeks. It will need to address quality, migration cost, and be a more compelling offering to users than Vista is to hold the line, otherwise Microsoft will bleed share how much will depend on how good the alternatives are.
We may be saying goodbye to products like Ubuntu Linux, but the code will live on in products that will seem even more tightly controlled than Windows in order to address the quality problems that have plagued Microsoft, but are more Open than the Open Source-based MacOS.
The irony in all of this will likely give us much to comment about in the New Year. Here is hoping we are all around to enjoy it.