Magic ward : Choose an opponent's zone. Treat the printed text box of each unit in that zone as though it were blank (except for traits) until the end of the phase.

Grimgor Ironhide : After this unit enters play, destroy all support cards and developments in each player's corresponding zone.

Suppose I play Magic ward at the beginning of my opponent's capital phase and blank the text box of all unit in, say kingdom zone. My opponent then plays Grimgor Ironhide into the Kingdom zone. Does Grimgor Ironhide retains its Forced effect while entering play?

A similar situation is when my opponent is playing Grimgor Ironhide into a zone (which triggers an action chain. p11, FAQ, Entering Play v 1.4), and I follow up this action chain with Magic Ward, which resolves first due to last-in-first-out rule.

I would believe that the Forced effect does not trigger due to the fact that I was not actually trying to cancel it. Magic ward merely blank out the text of all unit in a particular zone, which was already resolved before Grimgor Ironhide may enter play.

Any thoughts?

Yes it blanks both ways. Whether you play magic ward before grimgor or in response (because the ward will resolve first)

cool! now that makes Grimgor a little less fearsome hehe