There is two ways to look at it. If it does come june/july we can almost bet it will be full of bugs sigma has never released a fully working sdk/chip at launch, If they are truly trying to get into into $2000+ market, It wont be out june/july as no one dropping $2000+ on a media player will go for bugs so they have to make it bug free from the start.
Marvell does support samba but not for iso unless it has the BD license But the marvell sdk is far worse then any sigma sdk, passthrough audio does not work at all on the newest armada 1000 sdk, I would wait at least a year before looking at another marvell product this is there first push into media world to fix all the kinks,
The main thing to watch for is things like the Armada 510 based CuBox coming out. They are getting fast enough and cheap enough to make a low powered silent xbmc box,