-JNJ exited the stent market because JNJ had an inferior stent and couldn't compete with BSX.
-JNJ exited the stent market in order to clear anti-trust hurdles if they were to now buy BSX.
-JNJ sent their top medical device executive (Mahoney) to sniff around at BSX and become BSX's CEO in November.
-BSX has reduced it's longterm debt from 6 billion in 2009 to 4 billion in 2012 to become more attractive to a potential suitor like JNJ.
-BSX has initiated a stock buyback plan in order to reduce the float and make an acquisition more attractive to a potential suitor like JNJ.
Even if JNJ was to split up it's medical device unit into a standalone separate company, they would still buy BSX. Abbott is also separating out it's medical device division into a separate company. BSX could be bought by both JNJ and Abbott, with JNJ getting the stents, and Abbott getting the defib business. Just remember that JNJ wanted Guidant. Now they can get it at a much much lower price.
That is my read on BSX. Target buyout price $10-$12.