Nope the requirements to play customs on dota 2 are honestly too weird.
To give you an idea what I mean read this.
http://www.playdota.com/forums/showthread.php?t=1433758The main thing is you can't just join a random game. You have to be on the hosters friends list. Basically you need a party to play the custom game you want to play and the hoster has to have really good internet/computer to support all the players playing.
Although if you're looking for info on games on the dota 2 current map projects there's this link.
http://www.reddit.com/r/DotA2/comments/ ... map_ports/Right now castle fight shows 2 stars which means its kinda playable but its still in the unpolish stages. Although I could be entirely wrong since the last time that post was updated was October 3.