Besides the Wikipedia & Facebook entries (read with caution [citation needed]), there is an article by John Parker (a member of the NY Dance Music Coalition) on the website FMQBProductions.net detailing the changes mentioned in the 1st post on this thread. According to the article, JVC Media LLC, the owner of Party 105, has taken over the lease of Pulse 87 from Mega Media Group.
Note that Party 105 has changed its call letters from WDRE to WPTY this week. The New York City station at 87.75 LP-FM will be called "Party 87.7" (new station logo contained in web article).
There is also an "Open Letter From Joel Salkowitz", now the former PD of Pulse 87, thanking everyone for their support for the station for the 20+ months of its existence.
Article + letter linked here (scroll to bottom/end):
http://www.fmqbproductions.net/dance/index.html
From Facebook, it seems that the date & time for the changeover will be on Monday 11/2/09 at 6am EST.
Thus it will shake out this way: (if all we read is to be believed):
"Pulse 87" WNYZ-LP-87.75 NYC Rhythmic CHR/Dance Music: Off the air
"La Nueva Fiesta" WBON-FM-98.5 Westhampton, NY/96.9 FM (Translator W245BA) Manorville, NY Tropical Music: adds simulcast on 101.5 FM (Translator W268AN) Plainview, NY
"Party 105" WPTY-FM-105.3 Calverton-Roanoke, NY Rhythmic CHR/Dance Music: adds simulcast on WNYZ (call letter change :-\ ???)-LP-87.75 NYC;
drops simulcast on 101.5 FM (Translator W268AN) Plainview, NY