The new IS technology is basically free. That why it is used on the EF-S 18-55mm F3,5-5,6 IS II lens. It makes no sense to produce two versions of a lens with a price difference of a few dollars.
Ok, that makes no sense.
1st reason why not..
Current EF-s 18-55 IS vs 18-55 III non-IS
2nd reason why not..
Old 24, 28, 35 primes vs new versions with IS costing 3x, 4x the price.
To my mind it makes no sense to stop producing a lens for which the R&D and tooling etc has been done, unless it's not selling enough to make it viable.
I have the 70-200 f2.8L and it was a perfect fit for me (don't need IS but want f2.8 for video) and am sad to see it go, but there are plenty kicking about used if any body is dead keen.
It was a good value lens in canons line up, whilst not cheap, the current range equivalent is essentially double the price in the UK. Yes it's a better lens, for all sorts of reasons, but if I didn't already have my canon 70-200 f2.8L I would be looking at a sigma or tokina equivalent instead.
And that is the choice Canon are giving folk these days...
They have done wonders at the entry end. The 1100D and 600D are brilliant value well specified cameras capable of great images, the 18-55 IS and IS II and the 55-250 IS & IS II are all the lens a lot of folk are really seriously likely to need, they are very very good for the money, and for the most part the upgrades are operational rather than vastly improved IQ. For folk who don't need f2.8s they are great.
For folk who do need f2.8's. Well you are going to need a lot lot more money in the future.