The opening credits was edited and shortened (the reviewer in the review isn't sure if the original credits are used on this DVD though, but the original credits played the entire "Thank You for Being a Friend Song" whereas the syndicated version has the song obviously cut, so I don't know why it's so hard to tell if it's the original or not), and the episodes themselves have material cut out of them - a common occurrance when a series is sold into syndication to allow more time for commercials.
One problem with the Will & Grace season sets has been that many of the episodes are the cut syndicated versions rather than the full-length, original broadcast versions, so it's nice when a company takes the care to make sure the original episodes are on the disc in their entirety.