If Novell repudiates any "indemnity" from MS and never acts in any distinguishable way to gain market advantage over other Linux vendors by such "indemnity" then they are GPL2 clear.

But IF Novell markets asserting that indemnity then they are in violation of GPL2, because they will be licensing/distributing GPL material to others who will have less rights to that same material than they.   Novell will have the right to distribute with patent indemnity, but their downstream recipients will not.   It makes no difference that the indemnity does not come from Novell but from MS as the MS/Novell pact makes that indemnity de-facto one purchased on behalf of their customers by Novell.

I think that if a GPL contributor to some package distributed by Novell sent a c&d based upon the above, Novell would have to honor it.   If someone filed suit, my guess is that the likelihood of Novell losting would relate strongly to whether they use that assertion of MS indemnity in marketing SuSE.

The flip side, as I posted on IV, is that were I ever sued for patent infringement for an open source package distributed by Novell for one of the patents at issue, I would certainly argue that MS is estopped from such by their agreement with Novell, that essentially MS has licensed all the patents at issue with Novell for any GPL use.  They KNEW and were presumed competant to know that Novell could not distribute GPL material without giving everyone the rights they have, and their direct statements subsequent to signing the pact make it clear that they do expect Novell to go on distributing GPL material that they allege would otherwise infringe upon those patents.  (IANAL I have no idea whether such would get off the desk, much less how far it would fly).