Amazon.com is now taking pre-orders for the Chess in Concert CD's (with a June 16 release date).
You can pre-order the disc CD here, while the CD highlights disc can be pre-ordered here.
A big thanks to Icethesite for breaking this news.
There's nothing about a DVD pre-sale yet, but you can sign up for an email alert on Amazon to be notified when it is.
** Update: the DVD can be pre-ordered here (with a June 16 release date).