Those first four are good predictions. I'll predict a Mega Dunsparce, because it is another weak pokemon that is a somewhat surprising fan favourite, like Sableye (although Sableye became powerful --at least in singles-- when it got Prankster in gen 5).
A gen III fan favourite could be Mega Tropius.
I too would love to see Mega Dunsparce and Mega Tropius.
And I'm wondering if they will do anything else with this primal reversion thing other than Primal Kyogre and Primal Groudon. I could see them leaving it as special for the version mascots (maybe throw in Primal Rayquaza) but I could also see them doing something with Primal Regis, or maybe even something with the fossil pokemon (maybe including Relicanth) -- dropping the Rock type on boosted primal versions of them?
I think Mega (or Primal) Relicanth would be cool. Even a Mega Evolution probably can't save Luvdisc.
Mega evolutions of legendaries don't really interest me much, although I do think Mega Regis would be cool. If the hacker from a few months ago can be believed, there are mega evolutions of Latias and Latios.
I doubt there are going to be very many new megas, but there are a lot of interesting things they could do.
I am hoping there will be quite a few new ones. Maybe not quite as many as were introduced in X and Y, but somewhere on that order of magnitude.
My actual mega wishlist (for the Hoenn dex) is probably something like: Masquerain, Golem, Delcatty, Machamp, Dodrio, Swalot, Torkoal, Grumpig, Sandslash, Claydol, Tropius, Chimecho, Xatu, Girafarig, Glalie, Corsola.
I think we'll see
Mega Milotic as a counterpart to Mega Gyarados. We'll probably see
Mega Salamence and
Mega Metagross (groan).
Mega Flygon might be cool. I like Flygon. Primal Reversion with Arena Trap!
