It would be great to have a block that can take an XML feed, parse it and display it. I'm particularly talking about XML feeds that consist of a selection of products from a supplier, so the block will end up displaying that selection on my site.
I know WordPress has at least a couple of plugins that would seem to do this relatively well:http://hytekk.com/cj-datafeed/ andhttp://www.datafeedr.com/.
In fact the latter would probably be the ideal choice - I don't know if something like this can be developed for C5?