Actually, I think its more a question if iTunes does support any way to read album art, than a question of a way, since wave files are simple RIFF files, and next to all those INFO chunks (INAM, IART, IPRD &c., see
http://www.geocities.com/smigman.geo/mci/riffmci.html), another chunk containing artwork would technically be quite simple. Maybe such a standard even already exists somewhere and just isnt known (just as real riff text metadata in wave is relatively unknown). I know of two workarounds only currently, which is either attaching a ID3v2 tag (silly since its not conform to the RIFF standard), or embedding the ID3v2 tag in a ‘tag ‘ info chunk, which might be seen as kind of a legit extension of the few existing info chunks, and which could actually contain anything that ID3v2 may contain… including cover art.
Is this worth a suggestion to Apple to support this? Not sure… it seems they already can read/write standard wave text metadata, but I’ve never checked if they even react to bug reports (hmmm… might check if they fixed the bugs I reported some months ago in their recent update).
To get to an end: there are currently two ways, one bad, one kind of acceptable, to embed album art, but without the client supporting it, they’re kind of useless 😉