David,
It is a bit hard to swallow, but if you really are interested, you have to read their entire plan (conspiracy theory is a good analogy -- it really is a plain in view world wide conspiracy!).
And, not just Xilinx must follow: the equipment Intel, ST Micro, TI, IBM, UMC, TSMC, etc all buy comes from the same "roadmap."
If it isn't in the roadmap, well, it has no support, and eventually, it will not exist.
Now, that may be too harsh, as some technology variants (such as 3-D circuits, a la Matrix Semi, purchased by SanDisk) did make use of the existing roadmap, with some minor tweaks. Even there, is this profitable? The jury is still out.
As for what to invest in? Wow. As an engineer I made a rule for myself: let someone else do the investing! My judgment in that regard has been proven to be absolutely TERRIBLE. Any engineer who thinks they are a good investor, I haven't seen one yet! It is hard enough to stay current and be an expert in what I am supposed to be an expert in, let alone deciding to be an expert in something unrelated.
Good luck,
Austin