Mac's are not exactly flying off the shelves. Everyone's skint...
That's the same as in the last five years. As my mother used to say, "we are poor. We can't afford to buy cheap things". When times are hard, you look very carefully where to spend your money. People still can afford spending $1000 on a MBP; they can't afford wasting $500 on a laptop that ends up not being used because it is rubbish.
Mac sales have been growing. Even if it is not growing, Mac marketshare is growing, and the major case for sales growing less than previously is the success of the iPad, so Apple isn't exactly suffering. Just like Apple isn't really worrying about shrinking iPod sales, because most people who don't buy an iPod don't do so because they are buying an Apple iPhone. And it has been noted that Apple makes more money selling Macs than Dell, HP, Lenovo, Acer and Asus combined make selling PCs.
They're great pieces of kit but they are undoubtedly overpriced now especially given the difficult economic global background and the emergence of tablets as viable and cheaper alternatives.
See, you are playing tricks here. You make an unfounded and unproven claim (overpriced) and than add the word "undoubtedly" to it. No, they are not undoubtedly overpriced. Most people doubt very much that Macs are overpriced. Actually, not only do they doubt it, the people doubting it are correct. Apple doesn't make cheap computers. But when you compare Macs to similar products made by others, it turns out time and time again that Macs are actually excellent value compared to quality products made by other companies. When the Retina 15" MBP was released, which is not cheap even to Apple's standards, I went to Dell's website and tried to find a comparable product. While Dell offers many, many cheap laptops, something comparable to the Retina 15" MBP (quad core, similar speed, same RAM, same SSD, 1920 x 1080 screen, no mention of weight and battery life) was actually more expensive.
No. The average Mac buying consumer or business user wouldn't know what Haswell is.
Whatever it is, it is not a big jump that makes a Mac with Haswell processor an entirely different beast (unless you are into high performance computing or do quad precision maths calculations, where FMA is an absolute killer feature. iMac with Haswell could be capable of 200 billion double precision floating point operations per second). You buy a new Mac when your old one breaks down, or when the difference between new and old is big enough. And that just takes three years for some, five years for others. For switchers from Windows, Haswell is at most 5 percent of the reason to switch.