Updated Aptana in STS this morning and now have a slew of warnings. They don't show up in the Problems area, however.
This one is perplexing. Until today, the proposed value of the disabled property was "disabled". Now, "disabled" produces an invalid value warning and the proposed values are "true" and "false".
I'm not that up on the standard, but I haven't seen, anywhere, that HTML5 properties can be "turned off" by specifying a value of "false". This appears, to me at least, to be a serious error.