I voted "no I will never buy games that require it".
I've thought about it long and hard with several games before coming to this decision, so I shall explain:
Reason #1: Will steam/impulse/etc be around forever, garenteeing my ability to play the game I've purchased in the future? That's a big gamble. I love going back to games I've previously played....Master of Magic comes to mind. I'd hate to FINALLY get Master of Magic 2 in the form of Fallen Enchantress, play it for 5 years, and then find out that the service is no longer going to be supported forcing me to go back to Master of Magic 1.
Reason #2: Internet connection is dynamic over time. Things are changing with the way the world accesses the net. In the forseeable future, you have will have to purchase per gig instead of per month. That will directly increase the cost of playing online games. I MUCH rather keep the game disconnected, only downloading the patches as needed.
Reason #3: Playability of the game when I want. I want to be able to load the game and play..barring my computer being able to boot of course. I don't want to have to rely on a third party to ensure that the server is up and running in order to play the game.
Diablo 3 and Starcraft 2: Blizzard has chosen to go the route of battlenet in order to play their products, focusing on the multiplayer side of the game. This has resulted in less effort being put towards the excellent plot and storyline that there earlier predecessors had. Very unfortunate imo, and after demoing the games, I chose not to purchase them for the reasons above. Blizzard has lost a customer.
Skyrim requires steam to run and I have yet to bother playing the game. After reviewing the product, it seems that it's predecessor, Oblivion, is the better game. Steam downgrades the ability to get the most out of your experiance with a game if you have a computer that can handle it.
If FE were to go the route of steam/impulse, before purchasing the game I would look for a mod to enable me to play without the requirement of the server. If no such mod is possible (like in the case of Diablo 3), I will not purchase the game, much to my great disappointment...