Not really.  It all came down to exclusives and business strategy that made a difference and yes blu ray.  Blue ray was more for movies than games though other than a few like Metal Gear whcih was exclusive once again.

Rumors wise, I thought the only thing they had similar was the same exact APU

It doesnt matter if the hardware is slightly different like the X360 and PS3.  80-90% of the games are multiplat that doesnt really look different on whichever console you play it on.  The only games that looked different for the most part was exclusives.

Same APU means same CPU and GPU. Which is huge compared to the big difference with PS3 Cell that had much promised potential (didn't pan out due to cost but was BIG difference in the console's early image/reasons to buy)

Likely same 8GB of RAM. Bandwidth will be marginally lower because not GDDR5 but it's the amount that devs are asking for.

Blu-ray. Both have hard-drives on all models. Neither has hardware BC. These were all big things VGC clashed over in 2006.

The economics no longer make sense for exclusives that aren't first-party. Sony doesn't have the cash to throw around; the cost of porting is very very low now;  total dev costs are if anything higher; initial sales will be slower than PS3/360 and the small base of a single next-gen console just can't support an AAA title that wouldn't sell to a Halo-like fraction of the entire installed base.

Are there any announced third party PS4 exclusives? I'd be prepared to bet none will be released for two years.

FThey tend to get a lot of japanese 3rd party exclusives so I'm sure they will.  MSFT will likely be buying timed exclusives often in the beginning of the gen like they did with X360 which has proven to be a good strategy.  If sony can afford it they may try doing that as well.

I had a conversation with someone within the Xbox team not too long ago, and what I can offer from that conversation is that Microsoft will be doing something along the lines of an Xbox social network.

Achievements will be scalable as well. Meaning an achievement will have different values based the skill level you play. Play it on an easy skill level and you'll get fewer Gamerscore. Play it on hard and you'll get more. You won't necessarily have achievements that only are available on the most difficult level, instead if you want to get the maximum Gamerscore you'll need to play on the hardest level for an achievement. Don't know if that means you can get all the achievements on the easiest level, Then later on a higher level, or if you only earn them on one level.

Then why is PS4's rumored at 1.84 TFlops and the nextbox like 1.2 TFlops if they have the same APU?

Is it clock speeds?

GPU shader count. But it's like a PC - a game made to run on a $100 graphics card with 120 shaders will run just fine on a $200 graphics card with 180 shaders. There's almost no effort to port between the two this gen, though yes PS4 will be slightly more powerful.

O I know the question of porting shouldn't be an issue (unless they build the nextbox ass backwards), was just wondering the specfics. 

Thanks.