Is he into her? When a guys signs off "talk to you soon"?

When a guy signs off an e-mail, is there any significance to "talk to you soon" or "take care"? What would be the difference here? What about if a guy talks to you about a future event a year off but doesn't seems to be initiating e-mails but always responds within a few days over a long period of time? Is he into her? Is he thinking friendship, potential long-term relationship, what?