One other issue is that willingness to sell 10G is one vital competitive distinguisher in an otherwise largely commodity transit market. There have been rumors that older legacy carriers wish to punish more agile competitors for daring to "steal" 10G customers away from them, in spite of the fact that those older carriers have lots of trouble delivering 10G.
There isn't anything new to that either. I can think of (similar to Sean's story) a time when a backbone had all NxDS3 links in their network and used to be very upset at the idea of selling OC3s instead of NxDS3 ("If its good enough for *our* backbone..."). Then this network went ATM on Fore systems boxes with handoffs to Cisco routers to leapfrog their competitors... which um, didn't work... Then they reluctantly went POS and "better" systems since... They are still around today after about 6 name changes. I have no present-day-knowledge of their network or, really, their performance, so I don't want to mention any names. Deepak