Whoops, forgot to answer it properly! Well, if you're still interested...
Yes, there will be multiplayer support in GW. However, it'll be unlikely to make it into the first release. While I know that might be a little disappointing for some, there are several reasons for this:
Firstly, I don't believe in just tacking on some rushed multiplayer game option just for the hell of it. In my opinion, a decent multiplayer FPS game for PPC would almost be a seperate project in itself. Unlike something like, say, a racing game where the cpu-controlled cars are essentially just replaced with human players, an FPS benefits hugely from maps, skins, etc designed specifically for deathmatch, which take into account issues like lag, flow of gameplay, different game modes (ctf, etc). Support for 'bots' would also be included.
Ideally, I'd also wish to support differing connection methods inlcuding WLAN, Bluetooth, GPRS, etc and writing decent networking code to support the different methods would also help delay GW's release if multiplayer was included in the initial release. I'll also be receiving a Sendo Z100 before the end of the month, so I'll be looking at adding support for smartphone devices. In addition to this, we've been approached by a company specialising in 'connected' services so things could get very interesting...

Basically, a multiplayer-enabled GW would delay the release indefinitely, although adding much. In fact, it could even turn into a 'GW Arena' add-on update, allowing players to stick to SP-only or DM-only games if they so wished, thus saving storage, etc. HOWEVER the priority at the current time is to focus on delivering an immersive, playable FPS single-player experience i.e catering for the majority of PPC users. Multiplayer will follow soon after, i promise...
(Told you it wasn't a one-word answer...

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