Powerpoint presentations can be saved out as quicktime movies. Use Inframe to select the relevant frame.

The Decklink Intensity card can capture HDMI in YUV and RGB... If your powerpoint laptop can output 720p60 (aided and abetted by with a DVI Detective), you can get a DVI to HDMI cable and capture your laptop output in real time through Catalyst using video input. I have been using the Decklink Intensity with a DVI source all summer.

Hugh