friendfeed could be seen as a some sort of ultimate mash-up. Mashups have some real potential & they are not explored well yet.
Agree, Friendfeed's idea of aggregated mashup stream, with the content and the conversations it generates is new I guess. - Mahesh CR
I believe a Mash-Up version of facebook (social network) with some good added features & privacy & ... could become much stronger. - Nikpay
Agreed. What FF is really missing is privacy and compartmentalization story (as in feeds for relatives vs friends vs cowokers etc.) - andrei_c