is Iphone comming out with one with a slide out keyboard?

Apple has not announced anything like that. Anyone that knows is likely under a non-disclosure agreement so can't say. There are other companies that make slide out keyboards for the iPhone4. For example:

http://www.geeks.com/details.asp?invtid=BT-KYB-PHONE&cat=CEL

and

http://www.thinkgeek.com/gadgets/cellphone/e66e/