Yep, I’d do a 2 column container, the left is left-aligned and just big enough for the logo, that will allow your logged in menu to grow as much as possible before overflowing to another line, and then simply right-align the right block will keep your log in/logged-in menus (maybe toggle a hidden class based on whether the status is logged in or not).
Currently I’m using link blocks for the menus since we don’t have lists yet.