Concerning Nick:
This is from the premiere:
[ame="http://www.youtube.com/watch?v=9kiIa453ht0&fmt=18"]Red Ranger's First Morph[/ame]
And this is fanmade but uses audio from the later episodes so it gets the point across: [ame="http://www.youtube.com/watch?v=60RRs7cKIzs&fmt=18"]SPD Vs. MF Rollcall[/ame]
I never really understood the rephrasing either but we're kind of getting off-topic here.
Power Rangers has done rollcalls pretty much since the beginning, just not as often as the Sentai counterparts. True, Sentai does it more often and with alot more "emphasis," if you can call it that, but that's because it's become a part of the genre and is a tradition for Super Sentai if not "super-heroic" tokuatsu made in Japan in general, so it can get away with something that would look a little "odd" and make it look far cooler than it should be.
Really I think Power Rangers has pulled it off best in Wild Force (which was mainly a translation of the Gaoranger rollcall only without the gratitous name pop-ups), SPD, and the Dinothunder/Ninja Storm teamup, with Mystic Force being fairly okay, but like in Magiranger kind of overdoing it. Jungle Fury was also good as it got to be creative with the Spirit Rangers but the actual phrases were a little dull.
RPM's rollcall (if it will appear at all) will take some work to fit in, after all they're currently fighting fairly non-intelligent drones rather than introducing themselves to a new semi-sentient enemy each week. Most likely it will appear either a few episodes down the road, once the team has fully set up, likely after the Zenith Megazord is rolled out, or after the episode 18 cut when the writing tone shifts a bit to the lighter side (though with the current lampshade-hanging going on I doubt many will notice).