There will always be a place in my Heart for a Vesta curry lol.
As for takeaways closing down or dwindling away, i can't say as i've noticed it, and from the way the immigration department keeps going on about "There's a shortage of Indian Chef's, lets import a few thousand", i can't see it happening.
The fact that there are more high end/posh Indian restaurants around now isn't surprising at all really, i mean its just the natural progression of things, a takeaway gets a good name>becomes a restaurant, can charge more> becomes posh restaurant, can charge more.
Its just business.