What will the Longhorn RSS Platform Sync Engine do with feeds that are not well-formed?
I suspect that it is too much to hope for for Microsoft to suddenly start respecting the widely ignored RFC 3023, so let’s put that aside for a moment.
If Longhorn follows RSS Bandit's lead and refused to process feeds that aren’t (locally) well formed, then this single act will likely send immediate and profound shock waves out to the entire syndication community.
If, however, Longhorn follows the lead of virtually every other aggregator out there, then the impact having a core platform service responsible for delivery of data to applications compensate for XML irregularities won’t be as immediate; but the impact will likely be even more profound and will ultimately affect a much larger portion of the larger XML community. Probably starting with web services, both of the SOAP and non-SOAP varieties.
Either way, we are in for some interesting times.