It's entertaining; certainly worth watching. Spielberg (the director) still knows his craft (but also disappointingly stoops to playing scary music to us when Agatha is about to open a closet containing a teddy-bear). But the acting is reasonable (Farrell is good; Sydow's character is a little trite, but I blame the script), the visuals and aesthetics are good, and the story is enjoyable, if you're not too concerned by logical paradoxes in temporal matters.
IMDb reports that Spielberg consulted a crack team of futurologists; Spielberg should hire different futurologists, say I! Imagine this: a hyper-sophisticated visual display, manipulated by a "VR-glove" in several dimensions at once, requires a person to actually walk over from a console on one end of the room to the display on the other end with a silly Plexiglas thingy and stick it in a slot. We're talking 2054 C.E. and these guys haven't figured out a way to hook up the two machines. I mean, c'mon, we primitive humans of 2002 have had computer cables for quite some time now. Sure, Superman (in the movie) was cute when he fiddled around with all those crystals in his arctic hideout, but really, someone should have told Spielberg about network cables.
Plenty of cinematic intertextuality, too, if you're into that sort of thing: quotations of Kubrick, Blade Runner, cameos, motifs... The eye motif, for instance, is very obvious throughout the movie, but I enjoyed the whale motif much more, perhaps because it was relatively subtle.