For the record, I'm not sure the best place for MTGO related news to go.
Wizards announced the ratios at which "Curated Cards", which include online copies of the Power 9, appear relative to one another and in Treasure Chests as a whole. The link is http://magic.wizards.com/en/MTGO/articles/archive/magic-online/treasure-chest-card-list-info. I did some quick work with a spreadsheet to calculate the odds of opening a curated card. (Not going to calculate EV as that is much, much more work).
Probability of opening:
1 Curated Card = 22.62% = 1 in ~4.5 packs
2 Curated Cards = 1.19% = 1 in ~84 packs
3 Curated Cards = 0.010% = 1 in ~10526 packs
On average, each pack will contain 0.250 CC or 1 CC in 4 packs.
There are 681 CCs that appear at frequencies of 1 through 40 to each other. Notable Vintage cards at each frequency:
1: Power 9
6: Bazaars, Crucible, Dack, Doomsday, JTMS, Mana Drain, Zen Fetches, Tarmogoyf, Undiscovered Paradise, Unmask.
12: Ancient Tomb, Blood Moon, Cavern of Souls, CotV, Engineered Explosives, Force of Will, Golgari Grave-Troll, Grafdigger's Cage, Misdirection, Snapcaster Mage, Tangle Wire, Dual Lands, Expeditions
25: Daze, Pyroblast, Snuff Out
40: Gitaxian Probe, Preordain
After math, the probability of a curated card being a Black Lotus (or other member of the Power 9) is 1/7655 and you would have to open 30,585 Treasure Chests to find one (on average). While I can't (or won't...seriously, looking up the prices for every modern rare/mythic is bleh) calculate the EV of Treasure Chests or predict with certainty the impact they will have on Vintage or the MTGO economy, I hope this at least combats the view that WotC is flooding the market with Power and gives people more information when deciding whether or not to buy in or sell out of MTGO.
Please let me know if I mathed wrong. Peace.