There will probably be enough water in the main stem Arkansas to enjoy some III-IV+ on Pine Creek and Numbers, but historically our creeks don't come in until June. I can pretty much guarantee there will not be enough water in Clear Creek Ark to boat it in May. Here is the historical average flow for CC Ark for the month of May:
There is a better chance that the creeks around Durango will be in though. Last year Cascade Creek (which also contains the water of Lime Creek) didn't jump up until the very end of May, but historically it looks like it does normally flow during the period your looking at:
The Piedra will most likely be in....and that is a good time to look to northern New Mexico. Embudo Fest is scheduled for May 7th, so there is a good chance it will be in.