Sorry Mark..

But none of those links really correspond to the long term health of a development tool.
The only thing they indicate are as follows:

1. Product information for VFP is available on the MS website
2. 2 VFP exams are offered by MS that count toward earning the MSCD

To extrapolate this into anything more is pure folly...

The health of a development language can only be measured by its standing in the market place, how many people use it, what sorts of solutions are developed using the tool, how much has it been embraced/accepted by the business community. I could go on, but I think you get my idea here.