pureScale also on Linux
>> DB2 PureScale.. is available only on Power Systems at the moment – and only running AIX.
This is not correct. It is also available on Linux, but only officially supported with very specific hardware and software stacks.
The hardware in question is all currently IBM xSeries -
System x3650 M3
System x3690 X5
System x3850 X5
IBM BladeCenter HS22
The only Linux officially supported is SuSE Linux Enterprise Server.
I know of at least one company which will be running production pureScale on Linux before year end (if they are not already doing so).
Interestingly, DB2 Workgroup Server Edition licenses give you pureScale licenses included (for a modest number of CPUs : just enough to run a two node cluster), whereas it is an extra-cost option for Enterprise Server licenses. Obtaining some WSE licenses would be a very cost effective way to get your feet wet with what I expect will become an increasingly important technology.