no, not alot of maps can play siege. in fact, ive only seen two. (siegecastle, and the graveyard one), but if the siege part of DP could get bigger, and you could ask some of the veteran map makers to get in on siege maps more, then maybe later (like in a year or so) when siege was widely enough played, you could make the 3-siege idea come to life. I'm not saying it should be done right now, or even in the next few builds of DP, but if it could eventually be done, I'm sure if people tried it they would like it.
Also, pong/soccer was a huge waste of time for this game.. maybe the Halo community would have liked it.