“To go” still beats “to be like,” or “to be all like.”
Gotta give you that one.
That rule doesn’t work quite so neatly, though. For example, it’s proper to say “Give the sandwich to whoever wants it.” (It’s not whomever in that case.) I believe it would also be “whoever” in your sentence.
Oh, and cite.
As for “It is she” and “it is her,” the subjective case is correct, but in many cases sounds weird and stilted, as in “It’s I” vs “It’s me” and “Look! It’s him!” vs “Look! It’s he!” I’d reckon that while prescriptivist grammar may not have caught up with it, common usage probably heavily favors the objective construction. And using the objective case as a subject complement isn’t unique to English, either. Look at French with it’s “C’est moi” (“It’s me”) construction. There’s no real reason the subjective form has to be “correct.”
I’m going to use whomsoever instead.
Side tangent that happens all the time at work:
Angel: “And with whom am I speaking?”
Caller: “Huh?”
Angel: ::more clearly enunciated, slightly slower, lower pitched:: “With whom am I speaking?”
Caller: “Huh?”
Angel: “. . .who am I talking to?”
Caller: “Oooohhhh…”
Drives me nuts every time, because asking it that way isn’t something I’m doing consciously; it’s just what I was taught to do when I was a kid.
Anyway. Right there with you, CS. Carry on!
Cartoon in Playboy from the '80s: two women sitting in a cafe, captioned “So he’s all ‘You wanna get married?’ and I’m like ‘Yeah.’”
I think that’s a brilliant solution. And whomsoever disagrees shall just have to lump it. 
The bolded statement.* I do take issue with the suggestion that anyone who uses “whom” or “whomever” is doing so “on purpose” or in order to “sound” smart or more educated. It is just the way we were taught to speak (both at home and in English classes) and it becomes so ingrained that we (I, at least) give it little thought.
Okay here I was trying to avoid saying, “This!”. Any grammar neurotics* want to give me a suggestion on what is a suitable replacement when I want to say, “This” or “me too”?
**This is meant as a joke, let’s not take it too seriously, okay? 
ETA:
This reminds me of a conversation I had with my daughter over why she broke up with her boyfriend. She said, "He was all up my butt all the time, and so I was all like ‘you gotta go, dude’ and he was all ‘but I love you’ and I went ‘if you loved me you wouldn’t be up my butt so much’. "
And then Mom was all like, “what??”
Yourself should just be glad themselves were using a form of sex that isn’t likely to end up in pregnancy. 
I’m glad “whatever” is still allowed. Moved from The BBQ Pit to Mundane Pointless Stuff I Must Share.
Gfactor
Pit Moderator
Did I ever mention that Mrs M’s uncle played bass for The Whom?
Yeah, but “Whoooooooom are you? Whom whom whom? I really want to know.”
Whatever. Mkay.
Whom, me?
John Entwimsle?
Oh yeah! My favorite album of theirs is Thomas.
Whyever are we bothering about this? I’m just glad I can decode my friends’ text messages. (I have a proper keyboard; they don’t.)
The correct phraseology is:
- Who gots mah money!
For Whomever the Bell Tolls.
Just whom do you think you are, anyways?
Make sure they don’t have any calculators. They’re liable to start multiplying.