I agree with the sentiment about the labs, however I would also strongly suggest that you build your session schedule around two concepts:

1.  Take sessions that are relevant to the duties you perform on the job now.

2.  Take sessions that are relevant to the duties you WANT to be performing in the future.

For example, if you are currently seen as the subject matter expert for all-things Storage, you are going to find sessions about new storage-centric features for vSphere 5.x and can arm yourself with quite a bit of knowledge there.  And if you know that your employer or your customers are very interested in how they can leverage public cloud computing, then can use this conference to arm yourself with an understanding of how vSphere 5 fits into the equation and how VMware is positioning itself as a key player moving ahead.

I'd start with the Schedule Builder and do some key word searches to find things that are of interest to you. Once you have a few sessions identified via searching, switch over to the calendar view and fill in the empty spots with sessions that will challenge you, or push you into new areas.

One mistake new attendees usually make is they try to cram too many sessions back-to-back on their schedules.  This doesn't leave them much time to get between sessions and the Moscone Center is pretty spread out.  You're going to want at least 30-60 mins between sessions periodically just to grab a snack, take a restroom break, and make it from point A to B.

And yes... leave plenty of time for labs.