[Android Software/Hacking General [Developers Only]] Kangal:
Well firstly better hardware means nothing if the software is the bottleneck. Secondly, we've seen often the grunt of the cpu is more contributive to performance of programs than the gpu in Android OS. Thirdly, you're going to have to wait, see, buy, test these platforms to know which ones are superior... but here is what I've discovered during the course of 2010.

SoC's for 2011:

(listed in what I believe is the best to the worse)

+ ARM Sparrow: Dual-core Cortex A9 @2.00GHz (on 32nm die), unspecified GPU

+ TI OMAP 4440: Dual-core Cortex A9 @1.5GHz, SGX 540 (90M t/s)

+ Apple A5 (iPad2): Dual-core Cortex A9 @0.9GHz, SGX 543MP2 (130M-150M t/s)

+ Qualcomm MSM8660 (Gen IV Snapdragon): Dual-core Cortex A9 @1.5GHz, Adreno 220 (88M t/s)

+ TI OMAP 4430: Dual-core Cortex A9 @1GHz, SGX 540 (90M t/s)

+ ST-Ericson U8500: Dual-core Cortex A9 @1.2GHz, ARM Mali 400 (50-80M t/s)

+ Samsung Orion: Dual-core Cortex A9 @1GHz, ARM Mali 400 (50-80M t/s)

+ Nvidia Tegra 2: Dual-core Cortex A9 @1GHz, nVidia ULP-GeForce (71M t/s)

+ Qualcomm Scorpion (Gen III Snapdragon): Dual-core Cortex A8 @1.2GHz, Adreno 220 (88M t/s)

Notes: The SGX530 is roughly half the speed as the SGX535. The SGX540 is twice as fast as the SGX535. The Adreno 205(41M tri/sec) is supposedly faster than the SGX535 but slower than the SGX540 (thus, is likely to be in the mid). The Adreno 220 is twice the speed of the Adreno 205 but it is slightly slower than SGX540(88M vs 90M tri/sec). Samsung claims ARM Mali 400 to be 5 times faster than its previous GPU (S3C6410 - 4M tri/sec), about on par (80M tri/sec) with the Adreno 220, but few leaks benchmarked it to be only slighlty faster than the SGX535 (40M tri/sec). The gpu used in the Nvidia Tegra2 has been quite contained (little known). I estimated the Tegra2 has 71M t/sec (Tegra 2 Neocore=27fps/55fps=Galaxy S Neocore, x62% disadvantage of screen resolution, x 90Mt/s of SGX540 = 71M t/s). And recently some inside rumors via fudzilla actually confirmed this exact figure, so therefore the gpu-chip inside the Tegra2 is roughly equivalent to the MALI 400.

All of these details are based on officially announced, rumors from trustworthy sources and logical estimations, so discrepancies can be existent.

Last thoughts: As you can see there is some diversity in the next-gen chips (soon to-be current-gen), where the top tier (OMAP 4440) is roughly 1.5 times more powerful than the low tier (Tegra 2). However drivers and software will play a lead-role in determining which device could squeeze out the most performance. And this factor may alone favour the iPad2, Playbook or even MeeGo tablets to be better than the Honeycomb tablets which are somewhat bottleneck-ed by the lack of hardware accelaration and post-transcription through the Dalvik VM. I think we've hit the point where we could have some really impressive high definition entertainment, and even emulating the Dreamcast at decent/fullspeed.

edit2: Well, Apple's been boasting over x9 the graphical performance over the original iPad. There are 2 articles on anadtech, one in Geekbench and a processor-specific details from imgtech (I dug up from 12months ago). It has been found that its a modified Cortex A9, 512MB RAM and the SGX543MP2. Everything points to the SGX543MP2 being significantly faster than the SGX540, and the given number was 133 Million Polygons per second (theoretical) for SGX543MP4 which is double SGX543MP2 performance. The practical figure is always less. Imgtech said the SGX540 is double the grunt of the SGX535, benchmarks show the SGX543MP2 is (on average) five times the grunt as the iPad (SGX535). So going by imgtech (the designer of sgx chips), the theoretical value that I list above, should be 70M t/s ... going by Apple's claim it should be 200M t/s ... going by benchmarks it should be roughly 130 M t/s. Imgtech's value is definently wrong since they claimed its faster than the SGX540 valued at 90M t/s. Apple's claim also seems biased, they take only the best possible conditions and exaggerate it even more. It seems to be somewhere in between, and wouldn't you know it, the average of the two "false" claims is equivalent to the benchmarked value :)

edit3: The benchmarks are out for the 4th-gen QSD, which confirms everything prior. It's competing for top place against the 4440 and A5. I've changed the post (only updated chip's name).

If one were to choose between the processor of the A5 and the OMAP4440, they'd be really pressed to choose between more cpu grunt or more gpu grunt.