It's all a matter of personal preference. For me, I enjoyed having to plan my movements and keep track of how many TU's I had left. It wasn't about how the TU's matched reality, it was about the enjoyment of having to co-ordinate the varying movement points of individuals so as to accomplish the task. Setting up outside that airlock with three sqad members, one to open the airlock and two to the sides with enough TU's left to get reaction shots on any alien that pops it's head out.
The alien taking three in the back and still returning fire is not so much a problem with the TU system as it is with the AI. I would welcome an updated AI, but it doesn't require abandoning TU's altogether.
As for only having one base, I'm willing to give it a fair go, as long as the reported tie-in with the FPS version (that only has the US being invaded) doesn't require it to be in the US. Part of the charm of the original was being able to personalise the game to an extent by placing your first base in your own country. Forcing the base to be in the US would remove some of the charm of the game, for me.
Many fans of the original love the game so much 'because' of that brutality. There was no hand holding and no second chances. Accept a night mission and blindly walk your squad down the ramp without first throwing flares or smoke and yes, the AI would rip you a new one, but that's what EU was about, it's part of the reason why some of us still play the game now. Removing that tactical requirement from the game, for me at least, removes a lot of the challenge and interest for the game.
As I said at the start, it's all a matter of personal preference, but after watching the video of the devs discussing how much they loved all the brutal aspects of the original, and how they 'get' what X-COM was about, it's a bit disappointing to see so much of what some of us consider to be core parts of the experience being ripped out. I still have hope that they can make a great game, but my expectatios and excitement have diminished.
Firaxis' EU's lead designer, the producer and the art director discussing the original:
Edit: I now find out that ammo is unlimited. The tactical side of this game is shrinking with every reveal they make.