Well, the days of Canon/Nikon taking their own sweet time to update lenses is likely drawing to a close. They could get away with that before, since there was no real competition. Sigma and Tamron have not been taken too seriously by most enthusiasts/professionals for their inconsistencies in build quality, autofocus or whatever. This information would filter down to the average consumer, causing them to stick with OEM products unless budget restraints were critical. If this current rise in quality is sustained and not just a momentary aberration, this too will become well known and no company will be able to rest on their laurels. This is of coarse good for all consumers. The fact that Sigma is not just meeting, but improving over the OEM brands for significantly less money is amazing. For now, it is just in their high end models. I wonder if Sigma will be able to compete in the lower end of the market as well. That will really make Nikon and Canon take notice.
To steal a line from a previously mentioned "restaurant", I'm lovin' it!
I think you fundamentally don't get Canon's position. They are a multi billion dollar international corporation and are not overly interested in selling tens of thousands of lenses, they are into selling millions of cameras. Now the P&S cash cow is drying up they are repositioning into the C line, which is probably the only thing keeping any R&D going for us high end body stills shooters, and surveillance cameras hence the ultra low light sensor video R&D etc. They don't see Sigma or Tamron as competition because they aren't, they are comparatively small companies that sell limited quantities of niche products that you need a Canon (or Nikon) product to use, just like ThinkTank, or Adobe.
Where could I read more to get a better idea about Canon's fundamental position please?
Sanj, your comment is, I hope, tongue in cheek, just look at the release of the 7D successor, or if we want to keep the ideas to strictly lenses the 100-400, 35 f1.4L, 400 f5.6, 50 f1.4, a high quality ultra wide zoom, or even a decent sub 16mm prime.
To see how much pressure Canon feels from third party lens makers just look at where the money on lens R&D has gone, specialised high value lenses that set a standard for a system, the 200-400 f4 1.4TC, the 17mm TS-E, the MkII super teles, or for more modest uses, $500+ f2-2.8 moderate wide primes with IS, 24mm f2.8IS, 28mm f2.8IS 35mm f2IS. How much would you bet that the 45mm TS-E and 90mm TS-E lenses will take up the next significant lens releases? Canon are broadening the appeal of their bodies by pushing the envelop of specialised lens designs, they don't seem too interested, or in a hurry, to make competing lenses with the Sigma Art series.
You can make or agree with hyperbolic comments like "Well, the days of Canon/Nikon taking their own sweet time to update lenses is likely drawing to a close." or you can look at the ample evidence that it is not. Don't forget for one second Canon knows to the exact number the market for the 24mm f1.4 premium lens at the price point they are prepared to sell them at. Nowadays it seems the one who shouts loudest or wishes the most gets the most followers, that doesn't make what they are shouting accurate.