In Profiler 6.0 Milestone 10 the toolbar changed a bit - profiler toolbar has been merged with Build toolbar and Profile Main Project & Attach Profiler actions have been replaced by one dropdown icon with Profile Main Project as default action and Attach Profiler action available from the dropdown menu:
If you like the original toolbar with separate Profile Main Project & Attach Profiler actions you can easily change it to meet your needs. Right-click the toolbar in empty area to open a popup menu and click Customize..., it will open Customize Toolbars dialog. Find Profile category there and drag'n'drop Attach Profiler action to the toolbar next to the dropdown icon:
The same way Profile Main Project action can be added. Finally you can remove the dropdown icon by drag'n'dropping it from the toolbar to the Customize Toolbars dialog:
You can also create separate toolbar for profiler actions by clicking New Toolbar... button in the dialog and dragging profiling actions there.