Decks get more powerful as combos and power cards become available and less powerful as those combos and cards get rotated out. It's pretty unfair to directly compare a basics only deck to a standard deck, since you're using way less cards in the first set then there is in the second. (818 standard cards vs 372-382 original cards.) If you expand the basics and classics idea to also hold the first couple of sets to have the same number of cards as current standard, I think you'll find that quite possibly power has gone DOWN more then anything. Although that's not a totally fair assessment either because of how strong naxx and gvg cards were.
Also notable is that about half the cards in standard are classic or basic cards, and although this isn't an exact count by any means if you go and look at the top decks, it seems like often roughly halve the cards in them are classic or basic. There's isn't quite a "new normal" for playable cards at least. Although there are plenty of UNPLAYABLE cards that got power creeped on, that's not really effecting the balance of the game as a whole.
Of course, there's always outlaying cards to these general idea. I think anyone can see that cards like arcaneologest or meteor is pretty far above the curve power wise, and is pretty hard power creep on two drops. But that's not, at least yet, the norm for cards power level.
I think maybe the closest thing to power creep is the way that they've heavily pushed decks that can get themselves into an almost unassailable position. Things like taunt warrior, jade druid, and to some degree crystal rogue. It's not a totally new idea, jaraxxus did this as well, of setting yourself up into an almost unbeatable position where it's "do or die" for your opponent. But it's been heavily pushed (probably as an attempt to permanently eliminate classic "go 10 turns into fatigue" control decks and force the game to be more midrange to aggro as a whole.) I'm not sure if I'd call this power creep. In a way it's heavily pushing the late game power of these decks, and certainly I'd expect them to mostly crush the old control decks. But at the same time they are that powerful in general, and the old midrange or aggro decks should still do well enough against them.
Also you might be more understandable if you call mana and mana crystals mana instead of crystals. Maybe it's just me, but I don't think I've ever heard anyone refer to them as just "crystals". Mostly mana. Sometimes mana crystals. I had no idea wtf you were talking about in your first post, and it doesn't help that "crystal" is the name of a popular deck type right now. (specifically crystal or quest rogue)