To defend Tim, I want to mention the Osborne Effect. On the other hand, with a semi-predictable annual refresh there wouldn't be any cause for alarm that required a re-assuring word from him on behalf of Apple. We should look out for any news from the NAB show in April.
On Recode.net there's an article mentioning the average selling price of PCs is rising while average tablet shipments are falling. Although the PC unit shipments are similarly falling, those people who do need a desktop computer are paying more for a unit they intend to keep for several years, and there's a loose correlation with falling tablet sales which still have quantum leaps in spec on an annual basis but people don't want to be falling so far behind on specification.
I think a deciding factor in this is performance of the Cloud services which some people can't get their heads around or realise that they are sub-standard - looking at you iCloud...
Apple probably know full well that desktop buyers are keeping desktops longer and with average selling prices increasing they must surely be looking at giving consumers a PC that they would be happy to keep for 6 years.
So if the average Mini would-be buyer in this forum has a certain budget to spend (and let's face it - it's not $499), would keep their machine for upwards of 6 years (ok, not great for Apple but they get a chance to keep that person inside the Apple ecosystem with Apple Music, iCloud, the Mac App store etc?).
Updating hardware every 2-3 years in the computer world is just bizarre, never mind on a $499 Mini stuck on Haswell - what about the poor would-be Mac Pro owners who haven't had an update on their Ivy Bridge EP machine?
We'll soon be talking more openly in here about forthcoming Coffee Lake which will see 6 core options for both mobile and desktop Intel CPUs by early 2018.
In the meantime, Intel are partly combating the AMD Ryzen threat by offering Kaby Lake desktop parts that are clocked higher but with commensurate increases in power consumption. That's the i7 parts, some i5 parts could get hyper threading turned on like a cut price i7 and this is for parts which are likely available this summer.
Speed bumped parts could mean increases in TDP which in turn mean case/cooling system redesigns (and therefore form factor) if Apple feel that those parts are most appropriate for a redesign.
Regardless of this, a Coffee Lake solution for Apple in 2018 Macs including i7 desktops with 6 cores and 12 threads suggests an iMac Pro next year which potentially sees the Mac Pro base 4 core machine become very redundant.
