1. There seems to be very little question that the commercial Macsyma
property is in Andrew Topping's estate.
2. There is no doubt in my mind that there are some features, including
major revisions of some buggy subsystems, that have made commercial Macsyma
better for some tasks than Maxima (as it exists today). Just looking back
over the last few weeks of mail, ones that come to mind are limit, definite
integration, 'compar'. I do not think it will become incompatible with
Windows -- It runs fine on Windows XP, anyway.
3. I think that some people at Google and other companies are well aware of
Macsyma, Maxima, Maple, Mathematica etc. And even item (1) above.
4. The thought of buying commercial Macsyma to either revive it as a
commercial program, and/or making it open source, or making it LGPL or GPL
or "free" has certainly been discussed over the years by numerous parties,
including NSF, DARPA, DOE, ONR, NSA, and some number of foundations and
commercial firms over the years.
They each have their own reasons for altering (or mostly not) the current
situation.