Not only in terms of operating systems but all software, Microsoft has really stagnated.
That's what happens when you come too bloated. The innovations come from
the nimble software boutiques.
They haven't released a "must buy" OS or application in almost a decade. The only reason most people are buying Office 2007 is because MS changed the file format from doc/xls to docx/xlsx and it's no longer compatible. In other words, in previous versions, if I was using Excel 2000 or Excel 97, and my buddy was using Excel 2003 and he sent me FILE.XLS created in his version, my older version could still open the file format created by his newer software.
Yes and it's probably the default setting just like the much bulkier html verbiage
that comes with most e-mails. I can't stand the Windows approach of we know
best, we don't follow standards, and we're not upwards compatible. So I use
various flavours of Linux (come back VMS all is forgiven).
The downside is that you have to live in a M$-dominated world, so for instance
many online video and music services fail because they only use Windows Media,
although there are perfectly good non-proprietary routes as shown by the BBC
iPlayer and Hearts of Space.
Some safety person at work circulated a schedule of courses using that format.
OpenOffice couldn't read it. When our Division Head asked why I'd not responded,
I complained that the format was unreadable, and his response was Windows is
the Laboratory standard.

Trouble is that it's a moving feast and many scientists
use MacOSX or Unix/Linux. I was pleased to see in the last Departmental
newsletter advising people not to circulate Office 2007 documents. It would also
help if people just used plain text for most of the memoranda, saving lots of
storage and bandwidth.
Incidentally, a way around the above-mentioned problem is just to use Google Apps or Open Office, which will open .xlsx and .docx documents, and which will certainly server as a reasonable, free alternative to MS Office for all except professional secretaries or CPAs (and some of those).
I did try upgrading OpenOffice with some plugin for Office 2007 files but fortunately
I've not received any such files recently to test it. OpenOffice works fine for those
types of jobs.