I believe the notion of "creative destruction" is considerably broader than 
the notion of obsolescence, at least as the term obsolescence is usually 
employed.  I read obsolescence as implying technical decadence.  Creative 
destruction might well occur to firm's whose product remains technically 
cutting edge but does not meet emerging tastes or changing factor 
prices.  For instance, steam locomotives in the 1940s were certainly the 
best technically ever produced, however, their replacement by diesel 
electric locomotives was a consequence of escalating prices for coal.

John Howard Brown