I bought a PS1 a week after Launch, Bought my PS2 on Launch Day in Japan (3-4 Months before UK release, was living in Singapore at the time) and pre-ordered my PS3 for collection on launch day from Woolworths (remember them?), needless to say I have just pre-ordered my PS4 from Shopto £348.98, hope its November sometime.
Regards Backwards compatability with PS3 I am not at all fussed, I never played PS2 games on my PS3 so not being able to play PS3 games on my PS4 does not bother me in the slightest
The Kinect is something I know about, lost of the guys at the golf club have Xbox 360 and only one of them has Kinect, and for the guys who have PS3 none have the PS3 Eye, I don't think trying to justify the extra money for the Kinect is right as in my case only 10% actually use it and I am guessing that the PS4 Eye price will still mean its priced under the Xbox One.
Second hand games are worth considering, I play regularly with some guys from the Golf club (in the golf club itself lol, handy when the Golf Pro and head greenkeeper are very keen gamers), I also get free golf lessons from the Pro courtesy of him not being able to beat me at Tiger Woods 14
, they also have a 60" screen to use
) so they sometimes buy games and we play them on my PS3, when we are bored the game gets sold and we get a new one (Altho Fifa, Call of Duty, Madden and Tiger never gets boring), I also trade/sell older games I no longer use (bought on a whim and did not like).
I also play online with some mates and my brother (although only once or twice per month) and being lucky enough to have 50MB+ broadband the connection issue it not there (I can also connect at the Golf club using their Wifi), online gaming in the main is not for me, mostly its a bunch of yank kids giving it the "Big one", can do without hearing some spotty virgin trash talking
I had a Bluetooth earpiece for 3 months and soon left it turned off with volume down!.
The PS3 will pretty much live at the golf club once there are some decent games launched on PS4
There is always going to be brand loyalty (me) or those who don't want to change (me) and those people will buy PS4, it will be interesting to see how many from PS3 buy Xbox One and how many from Xbox 360 Buy PS4, personally I think there will be more of the latter due to price/limitations on Xbox One.