I know it's been asked for by various other PbP GMS, but are there any plans in the works for helping us to show/hide which aliases appear in the Post-As box?
'Simple' Favorites: I think perhaps the simplest implementation would be to add a "Favorite" check box next to each alias on the My Account page. Any aliases flagged as favorites would appear in alphabetical order at the top of the Post As drop-down. Any remaining aliases would then be listed alphabetically after a dividing line in the drop-down.
Numbered Favorites: Expanding on the above idea, the check box would be replaced with a numbered field like we have when organizing a wish list. Favorites would then be sorted according to the numerical value placed next to them. Any remaining aliases would then be listed alphabetically after a dividing line in the drop-down.