I would love to see an iServe, not powerful or anything, but say as airport base station with a hard drive for network backup.
More thoughts would be: a small darwinian OS for running services like apache, smb, afp, ipfw, printersharing, airport, bluetooth, possibly a firewire port if need-be..
stuff that only small offices or homes would need. Being able to use backup and isync locally and much faster than burning to a cd or transfering to a .mac account. I think it would be great for home use, but probably not practical for mass production and retail.