I send messages to my friend in the UK. Sometimes my messages come across as this number then mine. Others is shows up as my name (because he has my number stored). However the ones that come with this number are never delivered at the time I send them, they seem to be delayed and come at 3-4amGMT. At least he is getting the messages now. With the sudden appearance of this number, there have been more messages delivered late rather then him never receiving them at all.
I believe it is simply a router for when messages are being sent during peak times to help with the lost text issues. On Fridays we could rarely get a SMS delivered. This also did not occur while I was on Cingular Wireless. Only after the merge with AT&T did this begin and only recently. I hope this helps.