Europe is a lot bigger now so it appears to be more front loaded. We are looking at Europe growing for the market leader. 3rd year is usually the peak for standard priced consoles due to the US and Japan. A slim will most likely create legs for the PS4.

To put into numbers

Market leader in US 7th gen: 45-48m
Market leader so far 8th gen: 12m (25%)
Market leader in Europe 7th gen: 32-35m
Market leader so far in 8th gen: ~14m (40-44%)
Market leader in Japan 7th gen: 12.5m
Market leader so far in 8th gen: 2.3-3m (18-24%)

You can easily see why this gen might appear to be more front loaded, but it is simply due to growth in Europe (and RoW I might add), despite stagnation in Japan.

That's only if comparing market leader.

PS4+XB1 in USA, about 1/3 of lifetime PS3+360 sales

PS4+XB1 in Europe, about 1/3 of lifetime PS3+360 sales

PS4+XB1 in Japan, about 1/6 of lifetime PS3+360 sales

I could imagine a lot of "normal-gamers" (neither hardcore nore casual) bought a Wii last gen and stuck with it because they did't want to spend the money on a new system. This gen they are going with PS4 so this is what gives it the boost.
Xbox One only sells a little better than Xbox 360 so we can consider that as a natural growth.

Indeed, but if they were users that are no longer in the market, that would go with the theory that this gen overall is actually moving slower :) I do know quite a lot of "core" gamers who got the Wii as their first 7th gen system. 

Having thought about it a bit more. The PS3 retail price will have also held off sales they would ordinarily already have had. $599 or even worse as the (6 month later) EU release had it £425 launch price tag meant after the initial sales glut, sales plummeted. Once it was down the the acceptable sub £300 mark sales really picked up. (It took the PS3 over 6 months to sell it's launch shipment in the UK, as I grabbed a brand new 60gb PS3 just as they announced that model had been discontinued. I understand these were actually all launch units. The PS3 launched in March 2007 in Europe, I got my PS3 brand new from a mainstream retailer off the shelf for £350 with 2 full price games and a blu-ray movie in October 2007. The £425 was solus.

The Xbox One also tried launching with that sort of price, and quickly had to reduce it to stimulate sales.

It is most probably safe to say XB1 will sell similar numbers to the PS4 in the US, which creates the comparison of market leader+2nd place with PS4 and XB1.

93m vs 23.5m 25% yet again.

In Europe and rotw there will surely be growth.

In Japan, 1/6 is 2% off of the 18% so we agree there.

Compared to last gen, probably, but I think sales are more in line with what they had been in generations prior to the seventh. In all likelihood the ps4 and xb1 aren't going to be the slow burners with late peaks as we saw with the ps3 and 360 since there is no wii equivalent throwing off the balance. This year or maybe the next will probably be the peak years and we'll see sales start to taper from there on out.

I don't think this pace will be kept up but they will peak this year or next and slowly decline until their successors release.

Sales won't be Wii type front loaded and fall off a cliff although I expect the x1 sales to be more front loaded than the Ps4.

No, this generation wont be as long. It will last like the 6th gen, the PS4 will outsell the PS2 and X1 should do Xbox360 numbers or a bit less which would be impressive because the 7th gen was way longer

That seems very optimistic on both accounts.

In reality, PS360 was "behind-loaded". PS4+XBO is merely a return to the norm. But compared to PS360, PS4+XBO will be front-loaded.