Harry looked down at his empty gold plate. He had only just realized how hungry he was. The pumpkin pasties seemed ages ago. (Harry Potter and the Sorcerer's Stone)
It seems like ago is the peripheral modifier (CGEL,p436) as the examples in Webster’s. What I’d like to know, now, is if ages ahead can be a possible noun phrase that has peripheral modifier as above?
StoneyB's answer ("Ages away") works for looking at events relative to "now" fine (and carries a little ambiguity, possible to work into past or future.) For looking at events from perspective of time you can use ages later
Ages later, the breakfast came at last.
If you apply today, you will get a temporary permit sometimes after all your hair turns white, and a permanent license ages later.
The corresponding hyperbolic phrase in this particular syntactic context would be "ages away":
Breakfast seemed ages away.
That, however, could be used to express either prospective or retrospective remoteness.
This is very formal and antiquated, but Robert Frost used "ages hence" in The Road Not Taken:
I shall be telling this with a sigh
Somewhere ages and ages hence:
If we are referring to the far future, we might say "ages to come".
In the ages to come, what will our descendants think of these bulky laptops?
If saying "ages ahead" you must refer to what the subject is ahead of.
The scientist's research was ages ahead of that of his peers.
(In this case we are not referring to the actual period of time, but how long we think it would take his peers to reach the level he is at.)
"Ages ahead" can be correct use, in particular scenarios. That said, as noted in other answers, typical use would be some other variant.
If I were to use "ages ahead", it would probably be comparing two things rather than referring to actual time:
According to many myths, Atlantis was technologically ages ahead of all other civilizations at the time.
The sentence compares Atlantis to other civilizations that would have supposedly existed at the same time. It claims that Atlantis had technology that was massively more developed, as if from the future, despite being at the same time.
