The semiconductor business has changed, the glory days appear to be over and are not likely to come back. It is a different world now and no amount of nostalgia is going to change that. In particular, the old business model of fabless semiconductor companies is, for all practical purposes, dead, when it comes to start-ups and emerging companies (you can find more about it in this presentation: http://www.design-reuse.com/exclusive/kaben/). There is a need for new approaches that have a chance to bring significant ROI justifying investments.
Just because the old ways of doing business are no longer applicable, this does not mean there is not a need or a demand for semiconductor start-ups and their innovation - quite contrary! But the way we go about it has to be different. To avoid repeating myself, I refer you to this article: http://www.eetimes.com/electronics-news/4074052/Letter-to-the-editor-IP-cars-share-common-ground
The buyout portion of the plan is also tricky. A truly entrepreneurial company will always figure they are worth more than what the sponsor is willing to pay as a pre negotiated $$$ amount.
The sponsor has to already be interested in the company to be acquired, otherwise why sponsor. I can see the sponsor as considering Silicon Ventures sharing the risk somewhat for a "3%-5% return". It seems to me that the real value to the sponsor is off balance sheet development which they may have to absorb (the "buyout") later down stream.
To work, there would have to be many ways locked in to do the deal, and not many ways to get out of it - for both parties.