Hi All,
I just came across the following, and I found it so good that I thought it may be of interest to other people, too:
http://www.unc.edu/~jstimson/resource.html
It is a simple routine that allows you to convert a PowerPoint presentation into a beamer document - though you first have to convert PowerPoint to an outline/RTF file. But at least it will keep the slides transitions.
It is not perfect, though, so if anyone has any other tips on similar converters (from P0werP0int to beamer), I am all ears.