My ISP is now assigning non-routable IP's (10.x.x.x). I was told that this is only temporary because they will need to get another block of 24.x.x.x IP's. Has anyone heard anything like this before??

right. many .edu networks do this, but still block all incoming traffic by default and allow by exception. Sometimes there will be a lot of servers which serve http or ftp to the outside world, and ...