My new MBP Retina needs to be recharged after 2 1/2 hours
Open a support ticket with AppleCare if you'd like expert help in determining whether they can run diagnostics remotely to measure a few more data points than the overall summary.

It could be a high GPU / CPU / firmware thing that needs updating, but it also could be a battery that soon enough will show less life than designed and you'll be offered an exchange under warranty.

You can also open terminal and issue a few commands to look in more detail at power management.

 pmset -g rawlog

 pmset -g pslog


If you record the settings you have, correlate things with date; io_stat 300 you should get a good indication if the estimates are off and why. Of course, start with the machine 80% charged or more and let them run as your battery drains. AppleCare might not need all the logs, but you can send them / save them and run a check in 3 or 6 months to see if the battery is substantially worse / same / better than now.