Take it for what it's worth, but a Serbian publication called Alexander Raskovic, the agent for Jan Vesely that works under Arn Tellem, and asked the question many of us have been asking: will Vesely return to his club team Partizan if the NBA lockout goes on? This is a really rough translation from Google Translate, but I think you get the idea.
No further discussion or change. Jan is currently in the Czech Republic on holiday with his family. By the end of August will know the final decision. It could even earlier if we knew when to take lok-out [sic.] - said Raskovic.
I would imagine his deal would have an NBA out in case the lockout ends if he decides to return, but there's a chance things could be different because of Vesely previously being with Partizan. It's tough to tell. Thing is, though, Vesely's deal with Partizan expired specifically so he could go pro this year. If he returns there, I wouldn't expect a long-term deal or anything.
UPDATE: Raskovic sends this email to Michael Lee and also explains why Vesely didn't play for the Czech National Team this summer.:
"We are looking for the developing of the lock out situation, and by the end of the August we will make decision where he will play in Europe, or no," Raskovic wrote in an email on Monday. "Jan may wait for the end of lockout with no playing in any of the team]s] in Europe."