Will September's iPhone refresh be a true iPhone 5, a souped-up iPhone 4 branded as iPhone 5, or said revamp released as the iPhone 4S?
The debate rages still, but Chinese-language site Sohu reckons it'll be the latter - because Apple hasn't yet figured out how to get the iPad 2's A5 processor into the iPhone case and keep it cool.
The site's unnamed mole - they're not hard to find in Shenzen - alleges the A5 overheats when placed in an iPhone 4 shell, and so Apple has put the major upgrade on temporary hold until it fixes the problem. It'll pump out rebranded iPhone 4 tweaks in the meantime.
We're sceptical. The A5 is used in the iPad 2, and judging from take-apart pictures from iFixit.com, it's not like the chip has acres of space to pour heat into there but manages to run without overheating.
But, of course, the CPU is inevitably more space-constrained in the iPhone 4, and the A5, as 9to5Mac notes, is rather bigger than the A4 chip used in the iPhone 4. This is especially a factor if, as has been claimed, the next iPhone will be thinner and lighter than the current one. That would appear to rule out the A5
Apple may simply be waiting for a smaller dual-core chip to use in the iPhone - all eyes are on the A6.
Rumours have been flying that the next iPhone - or, more likely, the next iPhone-but-one - will feature a new case design, and that gives Apple ample scope to tweak the internals to facilitate heat dissipation.