Not a bind for a nuke (as that is a long way away) on my corruptor, but one that seems to make teammates laugh is the following:
"I'm pulling with Fireball, RUN FOR YOUR LIVES!"
The thing is, I mean it... 
my bind is
"RUN GUYS I'M ABOUT TO SPEW MY LOAD ALL OVER THE PLACE"
I use a series of .txt files that start with "Getting ready to go nova in ..." and then a count down from 5 to 1 with power exec commands for Aim and Build Up along the way. After the blast, my final message is " ... and I'm spent! All END donations gratefully received" 
The only time this failed me was when running in under my own Invisibilty rather than Granted Invis and failing to drop the toggle before the Nova should have kicked in
Luckily for me it was my usual team, so the following faceplants were not moaned about for too long 
Well I'm a defender, but hijacking the topic cos im more offender. Usually go for the EMP pulse followed by psychic wail combo to hold/ disorient/ damage while crying "Its time for the Elfling green and pink Disco Nova!".
I must also mention the hilarious naked nova of Krayster which includes a costume change (will leave the rest up to your imagination!)
Mmmmm My first bind not very original but got a few giggles "I'm Gonna BLOW!!!"
and my new one "STEP INTO THE LIGHT!!"
Sapphire Maiden lvl 50 Eng/Eng/Flame Blaster
Misstrix lvl 50 Fire/Rad/Ice Controller
Foundations Claw lvl 50 Fire/Fire/Flame Tank
Lord Viscera lvl 36 Necro/Dark MM/Flame Mastery
Kestrell lvl 50 Rad/Kin/Soul Corr
My Kheldians is "By The LIGHT!"
My Blasters......I don't know yet..he;s only 20..
Not mine but one I witnesses on a team.
"here it comes, and its a biggie"
Blammo
"Anyone got a towel?"
Better late than never on here 
Mine is "Time for some EXTREME CLEARAGE!!!"
Thing is people want me to go back to my old one
I havent got to the nova levels yet, but thinking that shouting "Smoke me a kipper, I'll be back for breakfast!" is a good un.
Mine is simply "My nova sense is tingling..." simple but effective =]