I dont think that the truemotion video codec from on2 technologies used by skype could be implemented considering the limited ressources the Nokia tablets have. This being said, on2 partnered with Texas instruments to bring a streamlined version of their codecs under the name hantro to the omap platform, the one used in the Nokia tablets, so that might work, when skype offers a new version of their PC software.
Much simpler would be to offer a google talk video client for PCs (and macs, linux, etc...), of course. H323 is a codec that works now...
