I like the idea it seems practical and useful tipping arrows with poison to poison things at a longer range which seems nice, but one thing could be that this capabililty of tipping arrow by a means of potions should extend to the other potions I believe should reach out to the other potion like a harming potion that could add some penetration of armor but not as powerful as a normal harming potion and the list goes on.
This has been suggested for as long there has been a suggestions forum. People have been dipping arrows into poison for as long as there has been a bow and arrow. This would add a whole new way to inflict negative potion effects on other players in PVP since tossing potions are completely useless since there is a very high risk of you getting splashed as well. You player can carry tons of stone but tosses potions like a 2 day old baby.