Adobe have released Reader 7, just the other day. This appears to be the most amazing thing since around version 3, the one on CD. Commenting features do seem to work ok for the sample PDF on their site. However, this is not the best time to write it up. More will follow in the second week of Jan.
Meanwhile the other Acrobat sites need an update as well. Future corrective action required to encourage people to check the blog if they think some news is missing.
Meanwhile, whenever you have the time, download Reader 7. Seems to load quirte quickly for one thing.Yahoo local search on PDF. Suggest you give this a try. Quite slow but may be quicker on later searches. No time to check this now as I need to buy some wrapping paper.