Both of the last two LCGs, Netrunner and Star Wars are asymmetical. Netrunner is much more so than Star Wars, but both games have their factions split into two halves that can never mix, at least some rules that are different for each side, and although the tournament rules for Star Wars are not out yet I expect both will want players to bring two decks and each match will consist of two games with the scores added together to determine a winner.
Thematically, an asymmetical game can have benefits - especially if the two sides are significantly different. But from a practical point of view it takes twice as long to play matches and with Netrunner I've seen a surprising number of posts about players who only want to play one side. In casual play these people can usually be accommodated but it would keep them out of tournaments and honestly I think it doesn't do much for the game's reputation. Someone who only likes one half of the game is unlikely to become a proponent of the game overall.
What do you guys think? Do you want to see more asymmetical designs or would you rather see the next LCG go back to a more conventional approach with symmetrical player roles?
If you like asymmetrical games, are there specific themes that you think would work really well?