"...I can't answer them right now though, i'm currently adding all the NQR2 achievements to the player profiles and i'm hunting down some russians to give me info on players. All i need to add are some KOFF players and some AMD players and i got NQR2 all covered for every player that was in a top16 clan. "

So, 5000 entries! Do you consider this a success or could the amount of contributions have been bigger by this time?

Well when you're talking about a project like a Wiki there's no upper bound as to how many contributers or contributions you can have. I'm not gonna say "it's all good!" when I know there are countless people out there that have heard of the Wiki but never even had a look at it, or they've heard of it and don't care. A lot of the sites we can/could snatch information from are down and/or outdated. That aside, browsing only gets so you far; Most of the information we need is nowhere but in people's heads.
But don't get me wrong, I'm not really bitter about since I can't blame people for wanting to devote their free time to other things than the Wiki. Bottom line: The more the merrier, but what/who we got for now is a pretty good start. 5000 is more than the official Swahili language Wikipedia. Up yours, Kenya!

Have there emerged any problems since the start of the wiki, perhaps concerning the increasing amount of contributors and contributions?

As I already pointed out in my answer to your first question, I'm more than happy about every new contributor we get, so I'm not gonna complain about the small issues that arise from the increase in contributions/contributors. Of course there are some minor issues like when among other things an unexperienced user adds a clan and lists Player XY in the roster but doesn't notice that there's already another player with that name (link from the roster will end up on the wrong entry), but that's just a formality. I'd rather see a new entry that isn't perfect or complete than no entry at all.

When working on the wiki i assume you have a core of users who do most of the changes. Has there been any natural (or conscious) division of different parts of the wiki (tournaments, players, clients etc) or is it free for all?

There's no real division when it comes to 'who does what' on the Wiki. Naturally everyone has their 'favourite fields' (UK contributors prefer adding UK players/clans, Swedes prefer adding Swedish players/clans, etc), but all in all everyone is free to contribute to any article he/she wants.

Does the wiki business get on your mind when you are as dedicated as some of you are? For example, if someone starts a new tournament, do you immediately feel an urge to document it properly so you don't have to do it later?

Yeah I guess that kinda applies. Adding a tournament or the respective results to the Wiki is always easiest when the tournament is still underway or has only recently ended. The info is still fresh and on everyone's mind, the dedicated websites are still up and all dates for everything are known. The sooner you do it, the less work it will end up being.

So, 5,000 entries...when will we see 10,000?

That's a very good question. It would actually be really easy to get 10,000 entries by just adding player profiles which is often just copy-paste (and it's tempting!), but you have to keep an eye on the quantity/quality balance too.
Right now I'm hoping for more contributors, especially for those parts that we have very little info on (North American QW, South American QW, Southern European QW, etc). Lately we've reached a peak of activity with a ton of great contributions so I'm hoping it won't be that long until we've reached 10,000.

One last question - what's your favourite wiki entry so far and what's your own contribution that you are most proud of?

My favourite Wiki entries would probably be those evolving around the NQR tournaments. Gotta love all the info and effort Purity put into those. It's great to have all the compact information from tourneys before I got into QW, with screenshots and everything. Love.
The contribution I am most proud of is probably that of the recently held "Ownage " duel tournament. All info, important results and links to demos on one page. I think I did a good job on that one.

When browsing it, i see that you certainly did! Thanks for your time, and good luck with the wiki business in the future!

Thanks for writing about it.