I upgraded a few months ago from my 7D to the A700. Now I'm sorry I
did. I looked at the D40 but thought that since I had used Minolta
for years, I'd stay with the A mount. Having some old Minolta lenses
didn't hurt.
Now I'm sorry I did.
Same old story. Lens available was a sore subject for years, but has only gotten better with Sony.
The 70-200SSM is $100 less direct from SonyStyle than B&H's price on the Minolta-branded version.
The 70-300G is hard to get right now, but looks to be a gem of a lens, not matched by the competition, and at least it's in the lineup. The fact that it's out of stock to me indicates that Sony can't keep up with demand, which doesn't quite equate to 'downfall'.
Tamron ? Not available, but a promising option. (It's also not yet available for Nikon).
Sigma ? Dpreview just posted that the 50-150/2.8 and 70-200/2.8 should be available in August. If Minolta were still at the helm, I imagine it would be ... oh, maybe never ?
Yup - the options are slim. The lineup is definitely lacking in the midrange (where most enthusiasts are simply going to buy Canon because that's what George Lepp & Art Morris shoot

But it's getting better & better with every passing month.
Sony wants to sell millions of A100's, 300s, 350s and superzooms to
go with them. Perhaps the A900 will rival the top Canons and Nikons
but that's not going to drive the advanced amateur, semi-pro, and
working pro who the A700 is aimed at. But I don't think Sony cares. I
think they want a Halo product that will drive point and shoot crowd
to them. Us poor schnooks in the middle? Not Sony's target market.
To an extent, you're right. I'd love to see an affordable prime kit:
35/1.8
50/1.8
85/1.8
Make 'em Zeiss lenses and you've got a killer attraction for the midrange crowd. Throw in a 70-200/4 option ...
Without the lenses in the $1000 range they'll sell lots of point and
shoot upgrades and maybe they'll lure a few top pros with free
equipment but all of us in the middle will be left with our tongues
hanging out. Unable to afford or need the $2-3k lenses and not
wanting the super zooms.
It's all about expectations. Sony's goals right now are modest. They're looking at around 10% of market share. They can probably get 10% with what they've got, and probably higher than 10% among consumers, closer to 10% in the midrange and maybe less than 10% at the high end (it'll also vary by geography).
At this point I'm sorry I didn't sell off my old Minolta equipment
and make the switch to Canon.
If you can't unload your A700 for an economically viable price, the lenses you've mentioned will be available in upcoming months. Sony's "downfall" is a snapshot in time; the current status of the lineup ... there's always tomorrow, and August, and so on.
FWIW, I've seriously considered dumping my Minolta kit 3 separate times in the past, each time before making a "major" (in my book) investment in more gear. I'm glad I never switched because at this point in time, the Alpha system (including the used market) offers me better options that suit my shooting style.
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