At least one (sensationalist) blog is reporting this adds 1800 hotels to WOH, but I don't see this backed up by the press release.

In fact, whilst Hyatt is very clear as to employees, the exact number of properties becoming available WOH is vague, hinting at more than twice the number of boutique and luxury hotels. Does anyone know the current approximate count?

I expect a portion of the MAMS hotels won't join, similar to what happened when SPG bought Design Hotels.