Verified answer

It's been confirmed by the site that there WILL be monthly payments.

"What about subscription fees? Will there be game cards for payment? Will there be a lifetime subscription? Will I be able to pay for a year in advance?

Warhammer Online will require subscription fees that are competitive with current titles. Currently we're in the planning phase of billing, and we're looking into various options including game cards and different subscription levels, but no final decisions about payment plans or options have been made at this time."

monthly payment like world of warcraft around the same price

I hope it's less than WoW, but there is definietely going to be a monthly fee. =\