Journey will be released on disc along with flOw and Flower in the Journey: Collector's Edition, which will retail at $29.99.
Bonus content will include:
+30-minute behind-the-scenes documentary about the making of Journey
+Creator Commentary play-throughs of all three games
+Three exclusive mini-games from thatgamecompany
+Concept art and screenshot galleries for all three games
+Original soundtracks for all three games
+PS3 dynamic themes and wallpapers
+PSN avatars including 8 exclusive new Journey avatars never released before
+Official game trailers and developer diary videos
+Reversible cover art
+One month trial subscription of PlayStation Plus
Seems like a pretty good deal, especially considering that merely downloading all three games costs you more than $29.99. I played the demos for Journey and Flower and enjoyed both of them, especially Flower, so I'll definitely be picking this up.
Also thinking of picking up the Ni no Kuni: All-In-One Edition, which comes out this month, as well as the PS3/HD version of Okami coming in November.