I think many consumer killer applications will come out in 2015, the ecosystem will be getting more comprehensive and perfect, fundamental factors will come out to increase its intrinsic value to support its price.

I try to be optimistic. I mean what else can go wrong from here. There is no more Mt Gox. People are gaining trust in the system. Microsoft is trying it out to see if it works. Not to mention Paypal. Forget about the price. If it drops, I'm sure there are many who are willing to buy at lower price, pushing it back up once again.

bitcoin 2015

The price will go up and down and up and down. Someone will come up with a new thin SPV client (as if I want to trust a full node other than my own) and no one will prune the blockchain to reduce its ridiculous torrent worthy size. Someone will release the news of another portable device, phone interface or card that holds Bitcoins to use at a store but the userbase won't grow enough for new devices to have value. Someone will release the news of a new Bitcoin NFC creation because all the phones are headed that way. 50 new scammers will be caught. At least 1/3 or more of them will be businesses. A couple of exchanges will fail either due to regulations or fraud/incompetence of the owner. The Bitcoin Foundation will be involved in another major scandal. A handful of new bugs will be discovered in the main client and it will be updated a half dozen more times but remain in beta. The forum will become more and more of a resource for law enforcement and the admin will get an increasing number of subpoenas for information to support current cases. BitPay will convince another handful of large corporations to accept Bitcoin using a zero fee deal. Small miners will continue to be pushed out of the market as technology changes and old pools die focusing the mining effort into the hands of fewer large pools and large farms. At least one country in the world will ban Bitcoin and one will welcome it. There will be 200 or more new "who's satoshi" threads.  

I can't wait to come back here in a year and check this.

it will sky rocketed because of the positive respond from big company

New ATH in 2015 around $5500

That would be truly awesome, could you name some reasons why you believe this is going to happen? If this really holds true, I believe it will happen due to pure speculation and the typical increase of media attention at some point, followed by a new influx of money.

I think by late spring we will see ATH

Yeah, this is mostly what I'm thinking as well. We had 2 serious bubbles in 2013 and I do get why the price at the beginning of 2014 may not have been sustainable at that time, but I do believe that we are undervalued at this time. If we go above $2500, I'd be content