With Haplogroup E(-V13), it's a bit unclear: it's possible that it was a Neolithic newcomer, but it's also possible it already arrived in the Mesolithic. As Sparkey said, there's samples of Haplogroup E-V13 from Neolithic Spain, so we know it must have been in Europe since at least the Neolithic. But what is peculiar is that there's little evidence for an ancient presence of Haplogroup I in Mediterranean Europe, so the Mesolithic origin may be accurate.
What is peculiar, of course, is that today, Haplogroup E-V13 is most common on the Balkans (especially in Greece and Albania).
With Haplogroup I, I'd say that all modern lineages are basically Mesolithic survivors inside Neolithic lineages that happened to be greatly expanded by later events: this applies most drastically to Haplogroup I1.
With the Neolithic hunter-gatherers, their dominant Y-Haplogroup appears to have been G2 - it occured in Derenburg, in Treilles, in that Catalonian site, and Ötzi the Iceman too was a bearer of Haplogroup G.
On R1b, I'd say "pretty darn early" is inaccurate: the oldest case of R1b thus far comes from a Beaker-Bell Culture sample from Germany. But I admit that we still have no clue where R1b was earlier and by what route it got to Western Europe.