Currently Being ModeratedDec 4, 2011 3:33 PM (in response to Tony Politano)
No, Time Machine cannot back up from a network location.
CarbonCopyCloner (donationware) can, and the ChronoSync app (about $40, I think) can.
However, putting other things besides Time Machine backups on the TC's internal HD presents some conflicts. See #Q3 in Using Time Machine with a Time Capsule for details and some workarounds.