Seems to Be Setting the Stage for Something Greater
Stan Lee and Jack Kirby seem to lose a little steam as the Silver Age draws to a close. Soon Kirby will defect to DC, and the Bronze Age will be underway a time when DC regains some footing, and Marvel and DC both have a more equal output of quality material.
In some ways Thor #154 hints at what's to come. It features a great Kirby / Coletta cover with a full color Thor in an action pose and a background field of Thor foes in monochrome. The story is just another in-between sort of issue. It happens after Thor and Loki's battle has ended, but before Thor starts a new fight. There is a lot of stage-setting going on here. Loki assumes the Asgardian throne, Hela gives Thor a preview of the place in Valhalla that awaits him, Karnilla turns on Balder, and Ulik frees Mangog.
It looks like Stan, or more likely, Jack, has at least one more great storyline planned for Thor.