I would recommend creating it as a series of web-pages, which uses Javascript or the meta refresh tag to cycle though the different pages. Simply full-screen the browser on a spare machine, and connect it to a projector/monitor/big TV.
This has lots of benefits:
- it's trivial to display images from an external server (an
<img> tag)
- it will cost nothing to setup (it can run on basically any functioning machine), and runs in a browser
- it is quick to do (you do not have to worry about cross-browser compatibility, or different screen resolutions as you know the exact machine you are developing for
- it's expandable - while what you describe is probably possible within Powerpoint, but if you do it as a web-page, you can use Javascript (or a JS framework like jQuery), and it's very easy to serve the pages via a web-server, then you can use any server-side scripting language.
Basically, you would have a series of files, say slide001.htm, slide002.htm and slide003.htm. Slide 1 would redirect to slide002 after 30 seconds, slide002 to slide 003, and slide003 would redirect to slide001..
The specific things you mention: graph generation and "Who broke the build" text:
Not sure which CI tool you use, but many of them generate graphs anyway, so that would be required is having one "slide" with something like <img src="http://hudson.abc/job/proj042/buildTimeGraph">
For the who-broke-the-build text, you would be easiest to run the slides as .php files served though a web-server, using XAMMP.
Then you would have a function that scrapes your CI server for whoever broke the last build, and in one of the slides, you would have <?PHP echo(who_broke_build()); ?>
(Obviously if you know some other language/system better, use that!)
The final benefit I can think of is that, if you serve the files through a web-server, you can allow people display it locally, say as their browsers home-page.