Regarding the Turbo Tank, my guess if Hasbro said it didn't do as well would be mostly due to retailer orders. I recall that thing being a good seller in my area, and then only saw a handful of them at various Wal-Marts on clearance right after Christmas. But I saw a lot more AT-TEs and AT-ATs marked down than I ever did Turbo Tanks... plus that sucker hauls in a lot of cash on ebay these days... a lot more than the other two.
Ok, I misunderstood some on the desire for a vintage-esque Death Star. Still though, rather than look at the vintage 3-3/4" one for inspiration, I'd actually be a lot more interested in something more along these lines in the 3-3/4" scale:
If it were modular though, I don't see any reason why they couldn't incorporate whatever play features they want (just make them hidden enough so they don't detract from the appearance).
Also one other point, price really is something that I don't get on Hasbro's end. I know a lot of toys these days are outrageously priced, but take a look at the Imaginext playsets... in particular, the Batman one... I wonder why Hasbro can't even do a Death Star for the Galactic Hero stuff, which would be the same scale as the Imaginext stuff...
Look at the Batman set... my son has this, and it's awesome... even better in person...
So, what does that thing retail for? $40-$45 depending on where you shop. But if that were a Hasbro item of comparable quality, there is no way in hell it would be that cheap, even it was GI JOE, which Hasbro owns the rights to. We'd have to shell out at least $75.00 probably... and for something that same size suited for 3-3/4" scale figures? I'm sure it would be at least $100.00.
Anyways, I do think there's more potential now than a few years ago because they made the business decision to price the AT-AT in the $100.00 range, but still... for a company with so many assets, and that makes so much money off this license, they really have wasted numerous golden opportunities.