I gave up on bitcoin after I started my new job and shifted my interest in other stuff.
Last time I was here moneypot started to get big and betterbets.io was becoming huge. I really don't have a clue when was this but I assume sometime before summer?
Since lets say all of 2015 , what are the major things that I should check and know before going in again?
The major thing you could've missed out is the max block-size drama, where no consensus can be reached regarding the future of Bitcoin. Gavin Andresen lost his leading position and the core devs mostly related to Blockstream took over the lead.
What else... 2015 was record year in terms of VC investment, 21 inc received the most funding.
Cryptsy is falling down.
Theymos is still working on new forum.
'Blockchain technology' is on the rise among financial institutions (but that's not really Bitcoin related).
Bitcoin found it's niche as a ransom payment system.
Moneypot is still around, changed the ownership tho
And that's all from top of my head.
Oh, and they've also figured out who Satoshi Nakamoto is, again. This year it was some guy from Australia (cant recall his name)