Cast X, if X is unavailable cast Y

[NYKnight]

I'm wondering if a macro such as this is still possible. In the old system, I believe it would have looked something like this:

/cast Revenge
/cast Devastate

If Revenge is lit up and not on cooldown, cast Revenge.
Otherwise, cast Devastate.

Is such a thing possible now?

Thanks very much.

[Dynatos]

/cast Revenge
/cast Devastate

Should (I think) work.

[NYKnight]

I've tried it on the test realm. All it seems to do is try to cast Revenge. I receive the following results:

If Revenge is lit up: casts Revenge
If Revenge is not lit up: "Ability is not ready yet."
If Revenge has gone off and the global cooldown is on: "Another action is in progress."

Very annoying.