I talked to the person in charge of coordinating 
the panels and workshops at Otakon and he told me 
there will be two cel-oriented panels this year. 
Unfortunately, given the tight scheduling at 
Otakon these events will be held at the same time 
as either MAT3K (Mystery Anime Theater 3000) or 
the Masquerade.

Quoting what I was told:
"The first is called The Animation Cel Roadshow, 
where people can have their cels "appraised" 
by "experts", most notably some cel dealers. 
After this, we will hold the second annual Cel 
Exchange, which will be for the purpose of cel 
swapping."

---Trebuchet