In Ezekiel 48, where he prophesied about a future temple, he talks about Kohanim and Levites serving. "Kohanim of the sons of Zadok..." or "Now for the Levites, opposite the border of the Kohanim..." ...
In a recent conversation I was told that the current Jewish calendar was only set till the year 6,000. There was conjecture as to what will happen after that time (assuming Moshiach has not yet ...
I recall learning that la'asid lavo the trees themselves will be edible (ta'm ha'etz k'tam hapri) as in gan eden. I cannot find the source for this though.
There are many mamarei chazal that discuss things that at one point existed and were hidden or saved for "l'atid lavo" (ex the ohr haganuz) does an extensive list of such things exist?