The Intel 510 works great in SATA 2 on these new machines as I have one in the Optibay (DVD slot) which runs at the lower SATA 2 (Apple limited it to this, for some reason).
Also, I read a post, where someone said that theirs run ok in Bootcamp but not in OS X.
If this is the case, it's actually good news, as it would definitely be an OS X issue, and we would only need an simple OS update.
But one thing is for sure; it could run in the new Macbooks, either with a firmware or OS X update (firmware to adjust the SATA controller; to either fix the 6 Gbps or limit it to a SATA 2), or a simple OS X patch.
But look at this logically. Apple releases a new line with new SATA controllers. The new controllers do 6Gbps. Apple's own SSDs don't do 6 gbps but are limited to SATA 2. These work fine so Apple is happy. But the problem is, the notebooks are clearly user upgradable, and anyone who puts a new (new is the key word here) SSD in them will find that they will 'automatically' switch to 6bps with a reset (as new SSD are all going to be this way). Problem is, OS X doesn't work correctly with 6 gbps , so ALL of the user installed SSD's will fail.
Bottom line is: Apple needs to fix this, like yesterday. Either that, or warn people that although their Macbooks allow the user to instal a hard drive, they are limited to rotational media: NO SSD's....sorry. If Apple says "We only support our SSDs", which they may say at first, this tune will change if enough people complain.( Actually, I think it would be a mistake to acknowledge major incompatibilities do to laziness

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The funny thing about all of this is, the same thing went on with the SATA 1 to SATA 2 upgrade a while back. But this time around it's worse, as with the previous conversion the drives at least worked, but only at SATA 1. (as before, the issue is only with SSD's really, as they are the only drives that can effectively use the increased bandwidth ). It only took Apple a short while of listening to complaints, and 'presto' a patch. Everyone was happy. But they aren't going to do anything until we start complaining. Intel isn't going to do it for us. The squeaky wheel gets......
Oh yes and BTW, I wouldn't go out and buy one of those attractive Vertex 3's quite yet. For two reasons:
1) they probably wont work
2) OCZ are a bunch of.......