Cytyc merger is very expensive and signals internal concerns about growth. One has to wonder why they really bought CYTC and, more importantly, why they paid such a big premium. Often these types of mergers take place to disguise lack of internal growth potential. While CYTC has some neat stuff (Novasure, Mammosite), it has a very large segment that is rather mature. While I don't think that the merger is in and of itself troubling, the fact that they paid so much (and made it accretive by simultaneously leveraging financially).
The stock trades on its own at 24X 2008 EPS expectations, which is rather low for this company. CYTC trades at 27X. The combined entity (with lots of debt) will trade at closer to 21X if the merger goes through (though the rise in the cost of financing could lower the EPS projections). Technically, the stock appears to be topping. I am presently short the stock.