not experimental, but yes, all /porting/* branches are supposed to be relatively identical components in there and hw specific. I don't think we want to follow the mainline kernel path to have universal sources so the code can run on every arbitrary hw platform, rather we might need an adapted MCE, PA/ALSA, whatnot else variant for each device, and we keep all those (obviously non-blob aka FOSS) variants in their according branches of /porting/* repos. For N900 it would contain only FOSS replacements of blobs, for other targets it may also contain hw-specific variants of already opensource bits