Sorry for the delay, but we were checking on this for you. We have tested NMSQL 5.2SP2 on Win2K8 R2 cluster setup and it is supported. I was told that this will be added in the next update of the SCG. Probably in the next month or so.
Thanks for letting us know!
To expand this original question, when will NMSQL5.2 SP2 support SQL2008 R2?
This is not listed in the latest software compability guide.
Last word I got from Mr. Jones was that NMSQL 5.2 SP1 and NMM 2.2 SP1 have been qualified with SQL Server 2008 R2 and that the SCG would be updated. I, like you, haven't seen this update - so I'll pursue that so it shows appropriately.
Thanks for the question!
Just wanted to reflect that I did find SQL Server 2008 R2 reflected as supported in the compat guide (pgs 69 + 81):
(Click to enlarge pic)