No, Mac Pro delivery dates aren't 'deteriorating'
Earlier today French Mac news site MacGeneration reported that international Apple store sites showed April as the estimated ship date of the new Mac Pro (that April time frame is now in the US Apple store). That's being reported elsewhere as a "deterioration" of the Mac Pro's delivery schedule. But before you panic, consider this: The backlog of Mac Pros really hasn't changed that much.
The Mac Pro only began shipping (in limited quantities) at the end of December, and almost immediately Apple developed a significant backlog. Demand for the new machine has been high, and it's understandable: The Mac Pro, with up to 12-core processor and mighty workstation-class dual GPUs, distinguishes itself from other Macs for certain types of content creation and computational work. What's more, its predecessor was put on ice early in 2013, so there's a backlog of Mac customers who have been waiting for a new high-end desktop.
Also, the Mac Pro is being assembled in the US; it isn't being put together in China like most Apple products. So far, there's only one assembly line producing the Mac Pro. Apple - and its US manufacturing partner for the Mac Pro, Flextronics - simply don't have the scalability of a huge business like Foxconn, which employs more than one million people (by contrast, Flextronics has about 900 people on its payroll, with plans to hire hundreds more in the coming months).
So it's little surprise the backlog isn't dropping. When iPhone 5s demand outstrips Apple's supply, it's not a big deal for Foxconn to put thousands of extra workers on assembly lines literally overnight to increase output.
But back to basic arithmetic to conclude: Apple has been averaging about a six week backlog for the Mac Pro for a while (some folks have waited up to two months). As of today, April is about seven weeks away. And don't forget, February is a short month. So if Mac Pro delivery estimates have slipped, it's only been by a few days, not by an entire month - what's more, it's in the ballpark of where it's been since the Mac Pro began shipping.
Certainly nothing to panic about.