Getting rid of De Bruyne would be stupid.
Depends on the deal in my eyes. This deal with Leverkusen would be quite bad, but then again, Chelsea was ready to pay 30 Mil € for Schürrle in the summer, which left most of the German fans scratching their heads.
There is another rumored deal in Germany, though. A deal involving Dortmund, De Bruyne and Lewandowski. This deal would make sense for all involved parties:
Lewandowski wants to leave Dortmund and make the next step in his career. Chelsea would at least be an improvement in terms of salary and also probably fame due to the higher popularity of the PL. I also think the PL suits his physical style the most.
Dortmund would not lose Lewandowski to their biggest rival and would get some cash plus a highly talented midfielder, who would suit Klopp´s system quite well.
De Bruyne wants to play in the CL, which would be offered by Dortmund. His chances to become a starter would be higher in Leverkusen, but I still think he would have the potential to become an important part of Dortmund´s squad. Klopp´s reputation of being one of the best talent developer in the world could also play a role here.
Chelsea would get their hands on a true top striker, who is after Falcao probably the best available forward in the summer.