I was thinking that given the iPhone 5's late September/October expected release, Apple would want to pad their GPU performance increase to meet potential challengers in the Exynos 5 series Mali-T604, Qualcomm S4 Adreno 320, and similar SGX544MP2 in OMAP5 which will all presumably be available later this year. Assuming Apple continues to aim to have top GPU performance on release of course. They may well be aiming for a more incremental performance increase and focusing their attention on the case redesign as the key product differentiator this year.
Let's see first if we see SoCs like OMAP5 and co in actual devices before this year runs out. Even if then in what kind of quantities?
As you note in another post Apple's headache for the next iPhone might not be only on the GPU side but also on the CPU side, since dual A15 at high frequencies (such as in OMAP5 at =/>2.0GHz) are going to be a tough cookie for quad A9s. Of course there's also always the sw side of things and since Apple has its own OS and hw is not obviously the entire story.
I also missed your 554MP2 question somewhere above; such a config is IMHO ideal if you have a workload with very high complexity shaders for today's small form factor standards, in any other case where shader complexity in applications is still mediocre the advantage to a 544MP2 at the same frequency could be by a lot smaller then the theoretical difference in FLOP amounts between the two might indicate (exactly because all other GPU aspects like texel, pixel and Z fillrates remain the same amongst others).
Rogue on the other hand is a totally different beast (obvious for any new architectural generation); it doesn't only rise FLOP rates by a lot compared to Series5XT but apparently also by a high degree triangle rates and texel fillrates amongst other things.
Remember also that you get from different sides a crapload of twisted marketing material; how long was it ago when in a freescale document the Vivante GC2000 was presented as being by a good marging faster than the MP2 in the iPad2 (while they'd obviously compared non vsynced vs. vsynced results ) and now that the Huawei U9510 with a GC4000 (twice the "cores" than the GC2000) made it to a product it's suddenly even slightly below the iPhone4S in Egypt.
Again I've no idea what Apple's intentions are, however it seems to me that if their next iPhone banks in terms of GPU performance somewhere in between the iPad2 and 3 it could very well be sufficient in order for them to stay competitive always in a relative sense. Yes competing solutions might beat it within timeframe N, but then again iPhone uber-next might beat the first again later on. Here I doubt that either Apple or other players in the small form factor market will go for a <1 year launch cycle. When any new product launches by N months later than another one, I'd expect the newer product to be better.