Captain Spud, I believe there is no mandatory speed limit below 10000' in A, B, and IFR in class C airspace. Therefore, it only applies to VFR in C, plus all flights in D to G. Of course, most TMA's have speed limit points, usually approaching the holding fixes (12nm before lambourne etc). However, these are flexible depending on the traffic, whether you'll be holding etc. ATC can waive the speed restriction at there discretion on departure and arrival.
On departure, if we are heading in the right direction, it's not turbulent, and we get no speed, I will normally wind the speed up to the FMS speed (sometimes up to 300kts).
737's have heated windscreens for added bird protection. The manual says that if the window heat stops working, limit speed to 250 below 10000'. This implies that Boeing are happy that the windscreen will survive SOME birdstrikes above 250kts. (Not a 50lb Teredactyl, obviously).
What height do flocks of birds NORMALLY fly up to (I know some geese have been up to 30000'), but is 5000' any more dangerous than 15000'? Most birdstrikes occur near the ground on T/O and Landing below about a thousand feet. In Western Europe, do that many birds fly above this?