Sounds like it went okay. One area that might still need attention is finding him some mental age peers at school to work with from time to time. The special ed teacher might work here especially as she sounds like she's very interested. I'd load her up with a full portfolio of his achievements not just the video she's asked about. Perhaps she could do a pull out once or twice a week with one or two particularly bright kids in 1st or 2nd. 2nd will probably be a better match but 1st would give your ds some class peers if he does do a skip next year (or later this year).

On the testing front it may be worthwhile talking to them to see if the testing could meet DYS requirements. If it does, and he has qualifying scores, it's a win for both you and the school especially as the school hasn't dealt with this situation previously. If DYS is an option I think he's too young for the WISC and may not have enough headroom on the WPPSI so the SB V might be the best option - the experts will know the answer.