You know what I find odd about this all? It seems like we've seen a bit of a role reversal in the market!
When the Playstation 3 and Xbox360 were on the way it seemed Sony was pushing the "more than just a games console" side of things, with catchup TV, online extras, movie streaming, the latest digital media support, etc; while Microsoft went for the "It plays games, and plays them well" aspect, where anything more was a bonus.
Now it seems though that Sony has gone back to the basics which made the Playstation and Playstation 2 such successful platforms. They've focused on making it what looks to be a very good console first and foremost, and then building on top of that with other new features as more of an afterthought. Microsoft on the other hand is shifting towards the one-for-all approach.
I think both have their good and bad features. For me ultimately Sony comes out on top, as I just generally prefer their approach based on past performance, compared to Microsoft (I can't remember the last time I booted my 360. It just sits there, acting as a very expensive paperweight!). The thing which will no doubt make or break it though will be price and launch date.
People like to have the latest gadgets. When Apple launches a new iPhone or iPad there's a sudden rush of people swarming to get them, regardless of any issues which may appear down the line (Looking at you iOS Maps!). The console which launches first will no doubt see a rush of people getting them, regardless of price, while others hang off for the cheaper alternative.
With online gaming being so prominent in the last generation of consoles I think that reflected this. The 360 was plauged with problems when it launched, but people still bought them in spite of that. I'm sure this was because it was the first to the market at the time, but also, with online gaming services increasing in popularity players wanted what their friends had, so they could challenge them to games online and compete without needing to be in the same room. As a result, when the PS3 arrived on the scene, many people had already taken up Microsoft's offerings, and had blown their budget for that moment. The overshaddowing of the Sony system must of had quite an effect on initial takeup figures?
But my point is, timing and then price will probably be the decider for a lot of people. It's interesting from my point of view though seeing some many serious Xbox gamers turning around and saying "You know what, the PS4 looks quite good actually!". I think this time around we might see a fair few people coming back to Sony. It's like an old friend who got shunned after all those years for the new kid, only for him to turn out to be a prat, and have everyone revert back to their old friend