Apple killed the 17" MBP. Do you think it will make something bigger than the 15" rMBP in a year or so?
Doubtful.
1. It never sold well
KGI analyst in 2012 "Kuo said sales of the 17-inch MacBook Pro amounted to about 50,000 units during the first quarter of 2012, compared to 1.5 million of the 13-inch models and 500,000 for the 15-inch models. Kuo also estimated first-quarter MacBook Air sales at 1.1 million units". He has/had better access to sales numbers than I do. Anecdotally, in my whole life I have probably met 5-8 people who own a 17inch MBP. It just doesn't sell, and isn't envied the way other halo products are. Everyone always wanted a 15 MBP, not a 17 inch (anecdotally). Meanwhile, many imac owners would take a MacPro upgrade in a heartbeat.
2. Its not portable, no matter what everyone says
Most people who want a laptop want something portable to take around. The push these days at Apple is small, light, powerful and mobile. 15 inch-13 inch laptops seems to be what people like. For the people who need bigger screens, higher resolution can satisfy many of them. As computing power improves, there is less and less need for the chassis space a 17inch provides, as smaller laptops can hit the sweet spot. The MBA is a hit with the power of a MBP just 2 years ago. ipads are a hit. Big computers? Not so much. I don't see why a bigger laptop be the right move/a seller from Apples point of view.
3. It ruins the lineup
Apple is very organized. Pros may want a mobile desktop, but that is an oxymoron for Apple. Apple products fit in a defined space. The Air is a small, light laptop. The 13 rmbp is supposed to be a full featured laptop. The 15 rMBP is full featured, powerful laptop. Also note the sizes: 11, 13, 15 just like small, medium, large. Just like the ipod nano, mini, and touch. Of course there are exception..the ipod classic is kept because it is a classic and has history, and likely super cheap to make. The ipads only come in 2 sizes due to the tablet form only really supporting 2 sizes; and even then, the iphone or ipod touch can be seen as an ipad nano. A "portable desktop" or "very powerful, large laptop", which the 17inch would be would be, is a 4th category that doesn't fit in the mobile line up.
4. GPU
Mobile GPUs are being pushed to integrated; equivalent processing, less power use, Apple will likely soon be all portable iGPUs, completing the simplification of their lineup to what I see is their ideal 1 board per line (no HDDs, drives, etc). A 17inch laptop would either tax an iGPU and not work or need a dGPU...necessitating a lot of extra logistics and going against their vision. Not to mention, even if it had a dGPU, it wouldn't be that great; Apple never puts cutting edege graphics cards in their mobile devices, choosing battery life over power.
5. No halo
While a 17mbp could be a halo product, sold in low numbers and made for prestige, it isn't. The 15inch took that spot long ago. It is their crown jewel laptop being a big seller and a halo. The issue is that a laptop needs be small and relatively light to be considered a "useful or real" laptop. In the publics and tech reviwers eyes, the 17 inch never was small or light compared to the 15 and it had nearly equivalent processing power and was just an impressive. So the 15 inch got the spotlight and the prestige. Like I alluded to earlier,I think desktop owners usually envy the MacPro, and would take one if cost was not a factor. The only downside of the MP is price. For laptops, I think most people would upgrade their 15, not get a 17. The downside of a 17 is that it is bigger, which many people don't want in their "dream" laptop
6. Nowhere to go
What would be the point, the killer app, the big seller for a 17inch rmbp? Desktop processors is out, the 15 has it. Dual chips would be too hot. More battery is not needed with Haswell and broadwell coming, as well as iris, since everything should be hitting 12 hrs. There would be little point of more in the larger 17, if it could even do it (since the screen and GPU would need so much power). No one needs 18 hr battery life in a portable desktop...its going to a desk. A dGPU opposes Apples direction. More storage, or an optical drive are being depriortized, removed, or replaced by wireless and the cloud. A 4k screen would be meaningless as the 13 and 15 already have retina and I don't think consumers would be able to tell the difference, and it would also be confusing eg "what makes 4k better than retina?". Most people can get all their mobile work done on a 15 inch screen that can be uprezzed to 17 pixel size.
So, while I personally harbor no ill will towards the 17, I just don't really see it coming back. It lost its spot. A great computer, but it was from back when laptops were 13, 15, 17, back when you needed space inside a chassis for large parts, back when you couldn't make higher res panels so you had to make them bigger.