There are 114 companies in the current YC batch.  We’ve grown too big for them to all present
on one day.

So, for the first time, we are going to have two Demo Days,
March 23 and 24.  We’re also going to
break the companies into categories—biotech, enterprise, consumer, etc—so that
investors can focus on what they’re interested in.

We expect that most attendees will attend both days, but if
for some reason you can’t, we’ll have option to register for just one day.  Also, videos of the presentations from both
days will be available to approved invitees for one week.

You can request an invitation here: http://ycombinator.com/demoday.