According to some reports Apple Watch will be released in March.
Tim Cook last year said that will be released in early 2015, According to Gurman Apple is working to boost optimize and a longer battery life.
IWatch will be compatibled with Iphone 4, 4s, 5, 5s, 5c, 6 and Iphone 6 Plus
The price of Apple watch it’s not announced, but it’s supossed to be from 349$-450$
But do not forget Apple is going to have Rivals like: Samsung Gear 2, Moto 360 and LG G watch.