Download the newest version from http://nxsfan.co.uk/MCEPopups/SkypeMCEAnswer.0.4.2.zip
While SkypeMCEAnswer works perfectly on my 2 HTPCs, I'm sure it isn't bug free, please let me know if you have problems!
If new to SkypeMCEAnswer, it is dependent on http://nxsfan.co.uk/MCEPopups/MCEPopups.0.3.msi
Original Post
SkypeMCEAnswer is an imaginatively named program that allows you to answer incoming Skype calls from within the Media Center interface.
The following image shows an incoming call:

When the call comes in the currently playing content is immediately paused.
From here there are 3 options.
1. Press Video/Voice:
Media center is minimized. Skype is brought to the front and switched to the incoming caller. The call is answered, outgoing video is enabled if selected and incoming video is enabled if available. When the call is ended by either party media center is maximized and media center automatically resumes.
2. Press Reject:
The call is terminated and a busy status is sent. The video resumes if automatically paused.
3. Do nothing:
After 30 seconds the dialog disappears. The following message is sent automatically to the caller: "This is an automated message. It seems no one is at the computer right now. Sorry!". Video resumes if automatically paused.
Installation:
1) First install the MCEPopups addin: http://nxsfan.co.uk/MCEPopups/MCEPopups.0.3.msi
2) Then SkypeMCEAnswer.
3) There is no installer for SkypeMCEAnswer, just double click on it to run, and add a shortcut to "Startup" in order to run on boot. To exit right click on the tray icon and select "Exit".
You will need to authorize SkypeMCEAnswer within Skype (it should automatically prompt after a short while).
DEBUG: While any errors are written to Error.log, you can get more detailed output by creating an "Output.log" file in the SkypeMCEAnswer root directory.
Changelog:
0.4.2 - Allows Unicode characters.
0.4.1 - Changed the method for activating the skype window.
0.4 - Control Skype with remote, fixed 30 second hangup bug.
0.3 - Enable selection of outgoing video/voice upon incoming call. If no camera is available the video option will not be available.
0.2 - Enable automatic pausing if content is playing upon incoming call