Interesting times ahead
OK so it's pure speculation but here's a few thoughts on what it could mean:
Sparc/PowerPC: IBM could ditch Sparc in favour of PowerPC but I'm not sure that would be a good idea: there are a lot of good things in the Sparc T1 and T2 processors. In particular, the T1 and T2 are more power efficient than the PowerPC so it may be worth deploying them in a power efficient range of servers.
Solaris/AIX: agree with you, it would make sense to merge the two and consolidate into one OS. The first hurdle would be to make Solaris run on PowerPC but it can surely be done.
Java: no brainer here, IBM has been a strong contributor to Java for a long time.
OpenOffice: no brainer either, OO.o is the basis of the latest version of IBM's Lotus Notes so that would give IBM the control of the whole stack, as well as a way to monetise it through Notes.
NetBeans/Eclipse: there are good things in both IDEs so consolidating in this space would be great. IBM already monetize Eclipse through Rational Modeler and friends.
Glassfish/WebSphere: there's some potential for consolidationg here too. Keep Glassfish as the open source app server, consolidate the Enterprise version with WebSphere and offer an easy upgrade path from one to the other.
MySQL/DB2: same sort of scenario really, consolidate, make MySQL the entry level option with easy upgrade to DB2.
Now that's my opinion and it may be complete dinkum but if there is one potential buyer that has a lot of synergies with Sun, it's IBM.