Now when you check the help area on the right of the administration window you will find the tray icon is gone.
When you want to batch assing elements now you just use the simple "ASSIGN' button that you will find at the bottom of any page where it is needed. For newsletters it is select customers button but works the same way.
Selecting products will open a new window in the administartion that will show all products. You can search in the window to look for specific products. You can select a product by ticking the selection box to the left of the product number. Once selected the number next to the Selected elements will increase (e.g. (3)) these are the products that you have selected. If there are multiple pages the selection from previous pages is maintained.
Once you have selected all the elemets that you need you can retain the selection by using the tick box "This selection is retained for further assignments". When you have everthing that you need selected you just click on the "Apply" button for your seldction to be used as needed.
You can select categories and sub-categories. By clicking on the sub-category icon that is to the right of the category you will open the sub-categories, When a category has sub-categories it is a link and clickable. To return you just click onthe higher level category name.
You can also use the same process to assign customers to newsletters. Of course you can also assign customers using the Customer Group, by Importing or by directly entering the information.