ESRLabs is working on Android Transport which would allow you to mirror the display of your Android tablet with the right chipset. You would then be able to use just about any output and have it show up on the Monitor. I saw one example where Netflix was being mirrored but I can't find it right off hand now.
Not sure what they actually will come out with but they are working with the Raspberry Pi and an Nexus 7 tablet (which has no hardware HDMI port). I think the need for hardware HDMI ports for tablets and phones is disappearing with a wireless solution like this becoming more prevalent.
What is available right now is as ghans said XMBC using something with Airplay support or UPnP.
I was playing with Short Beam (an Android App) the last couple nights which will display via XBMC on the RPi videos that are on the Nexus 7 tablet, photos, music, and has a YouTube player and Reddit videos... Works pretty decent though the app itself could use some clean up.
I can also do something like this with a notebook, though it is a dedicated dongle and receiver. Anything on the notebook screen gets mirrored to the HDMI TV. My son uses it all the time to watch Netflix, Amazon Prime video etc... he doesn't like Hulu but I'm sure that works as well.
ESRLabs demo of Android Transporter using a phone and the Raspberry Pi.
http://www.youtube.com/watch?v=lyoZoNA8U24