This is what they have said in their June 2012 newsletter…
Ever since Avid released their all new HDX hardware, our engineers here at McDSP have been hard at work to add AAX DSP and Native support to our incredible line of products!
The AAX support roll-out is just around the corner, so if you have not yet upgraded to v5, now is the time to do so! All v5 customers will receive AAX support for free! All McDSP v5 plug-ins are currently compatible with Pro Tools 10 running HD hardware (as TDM or RTAS), natively (as RTAS), and also on all Audio Unit supported DAWs.