I noticed the same thing and asked about it a few weeks ago. Someone said that the forums were being redone and that yes the marketplace will be back. It was someone named The One that answered but he/she didn't say when.
OK sorry about that people. I was unaware that the Marketplace was not showing up until someone mentioned it a few weeks ago. I thought I had it fixed but must not have saved the changes. I was able to see it but I guess no one else could.
It should now show for everyone.
The other forums (other than News) are being reworked. The rules needed to be updated to prevent some bullying issues, which is really the only thing I care about rules wise. Once that is finished then some general discussion forums will be added back in. Probably later this summer but certainly before the next TV series airs.