In my personal opinion, Bethesda went too easy on us. Ever realized why a dragons' vocabulary seems so limited and why they do not make use of FUS-RO-DAH (among other things)? Only the player and some select Draugr (always in interior cells) seem to make use of it. It's fun for the player in shouting enemies off a cliff, but when your enemies can send you cartwheeling off a cliff (or into space); it's suddenly a bug... Just because you do not like a certain feature in a game does not make it a bug.
Oh trust me, it's lots of fun getting FUS-RO-DAH'd off of a tall cliff. There are several mods already released that added many more shouts to Dragons btw so no need for you to do it yourself (unless you want your own take on it out there of course heh). Makes for much more challenging Dragon fights when you never know which shout they're going to use and believe me, getting hit with Ice Form or FRD on the edge of a cliff is a Bad Thing?. A few examples from my last game:
http://img235.imagevenue.com/img.php?image=50439_Skyrim_1346_122_218lo.jpg
http://img257.imagevenue.com/img.php?image=50441_Skyrim_1444_122_4lo.jpg
http://img226.imagevenue.com/img.php?image=50443_Skyrim_1465_122_343lo.jpg
http://img245.imagevenue.com/img.php?image=50444_Skyrim_1611_122_79lo.jpg
http://img244.imagevenue.com/img.php?image=50440_Skyrim_1439_122_461lo.jpg
http://img237.imagevenue.com/img.php?image=50445_Skyrim_1633_122_372lo.jpg
I've also seen Marked For Death, Dismay, and Disarm used as well but those are hard to get screens of. I've had them used against me, however and they are as un-fun as you'd expect when used against you. Dismay does nothing vs you as the human player of course, but any followers, summons, and NPC support you may have will instantly run and hide or cower in place when it's used. Disarm can be very annoying indeed when used in a Dragon fight but it's a shout available to us so it should be able to be used against us. And MFD can make you very squishy if it gets used on you, not something that is helpful to your survival at all.
I may see if I can add in some of the other shouts as well. Whirlwind sprint would be funny as hell to see with a Dragon, maybe Elemental Fury as well (for Dragon melee attacks when grounded). Animal Allegiance and Storm Call also seem like they would work well for the Dragons in a fight vs the player.