I love that you can get Google Alerts feeds in Google Reader.
I love that you can export and import OPML.
I love that you can get output feeds via public folders.
I hate that there are no filters.
My ideal solution would be to merge FeedBurner into Google Reader, and then mashup Yahoo! Pipes inside Google Reader.
The other thing is that there is no plug and play DBaaS expressly for web feeds; I would love to be able to accumulate custom DBs from feed items, and then be able to easily query them via API with feed output.