I certainly worry about that as well. Many people I play with build their armies one new unit purchase at a time over a period of years...i'd hate to see my favorite new wood elf player who only has a starting 600 point army to be forced to spend hundreds of bucks too soon due to potential model ranges being phased out in quick succession.
Ironically, I actually stopped my wood elf army altogether after the Khaine book, it might not have been a true squatting of the army, but it was close enough to make me skeptical of their future. This is a bit of a shame in many ways as it means that although I haven't sold any of them (tons of metal treekin, way watchers, etc), it does mean that unless the AOS leaves the end times rendered fairly moot, I'm incredibly unlikely to start them again.
There's a group called "Oldhammer" on Facebook, an awesome group with members going way back (most to 3rd or even 1st edition, heh, kind of feels like I'm talking about Slann), they seemed far less than impressed with the release and statements, although you didn't get the typical angst you might find on other sites, a number of them took offence to the "the end time battles are nothing compared to what is to come".
Mainly because this seemed rather rather patronising at best, as though the last 30+ years of warhammer are inconsequential and irrelevant. At worst it seemed to many that it was a "everything you know and love is getting thrown out, rather than re-written, here is a brand new system you WILL need.
I will also say here, that the negativity did differentiate itself as they didn't throw out insults or bring out the whine and cheese board, but put together constructive, nostalgia driven arguments as to how they felt about it all. The biggest proof of the pudding on this was that many said they will go back to playing 3rd or even 2nd edition.
Can't say the prospect of using 5th edition when my Stegadon had strength 7 attacks isn't a little tempting....
Although I'd be happy going back to 6th ed too.