I disagree with their projection: Why? Because hotspots will be so broad that they'll blend into large hotzones. This is one of those "if it succeeds, it really succeeds; if it fails, it shrinks" propositions. If Wi-Fi holds its own against mobile WiMax and 3G cellular data as those develop or deploy, then Wi-Fi increasingly becomes a cloud of coverage across areas of interest, such as the many municipal networks being planned and built.
200,000 hotspots would mean 200,000 unique locations: perhaps when you add up hotels, airports, and chain and independent stores, you reach those numbers. But I suspect the future will shake out into more clouds than points.
Perhaps more interestingly, In-Stat estimates nearly a billion in revenue from hotspots this year and $3.5 in 2009. This must include wired hotel rooms, as those continue to provide the bulk of connection sessions for hotspot operators who provide wired and wireless hotel access.