what this is spoken here in this verse is being spoken by god. This is evident in context.
verses 16 and 17 go together well and say nearly the same thing, giving you a little perspective on who exactly is doing the forgetting here: the same one creating is the same one from whose eyes the former things are hidden.
Keep in mind though that heavens and earth don't always mean the literal form nor the forms that JWs teach.
Of course this is all a moot point if you don't consider the bible as having a divine origin.
(from the KJV)
16: That he who blesseth
himself in the earth shall
bless himself in the God of
truth; and he that sweareth
in the earth shall swear by
the God of truth; because
the former troubles are
forgotten, and because they
are hid from mine eyes.
17:
For, behold, I create
new heavens and a new
earth: and the former shall
not be remembered, nor
come into mind.