Not anti-competitive
Last time I looked I could buy games in HMV, Zavvi, Woolies, online, and a bunch of other places as well as GAME/Gamestation, so its hardly an issue. As for pre-owned, anyone who buys or sells in Game OR Gamestation is nuts because eBay and Amazon Marketplace are way cheaper.
Its fairly obvious that Game bought out the for-sale-for-two years-already Gamestation as a spoiler to stop GameStop getting into the UK. THAT's the anti-competitive bit, but I can't say I blame them, its exactly what GameStop did to EB in the US and we can expect more of it as the market gets even more cutthroat. Game have put out very good numbers this week, but does anyone expect games retail not to go the way of music and DVD retail in the long run? This is just the market consolidation you'd expect in these circumstances.