This has some viability in tribal Eldrazi (maybe fish?). A part of me thinks it would be fun to put in a mentor list.
Edit: I though I should broaden the original post as this card deserves more.
As far as blue decks go the most common creature type is Human (by far). If your playing mentor equipping a Snapcaster Mage with this gains a lot of value. You could block and trade your Snapcaster with a Thought-knot Seer and with this get mentor. If the odds gave you got another Snapcaster that's kind of better.
The cool thing about snapcaster and this card is you can flashback the revealed cards. You could almost use this in a vacuum and play with only snapcasters.
The tribal decks (that rely on consistency) would be great with this also. it doesn't really matter if you get a Though-knot Seer a Reality Smasher or an Endless One most of the time.
This card also makes delve better, and Yawgmoth's will better.
I really like this card I do wish it did more as an equipment.