I think many new players will criticize the current system for obtaining spell point potions. The #1 reason being that buffing, reconstructing and just being a haste bot is not fun. Most of the new players think that they should be able to nuke as an arcane caster; and that's fun for them.
DDO is not 3.5e PnP. In PnP, you only have two encounters per day and each encounter with no more than probably 5 monsters. After two or three encounters, the wizard or cleric gets to rest and regain ALL their spell slots; or spell points in this case. Where as in DDO, the whole dungeon is more than 2 encounters, and more than 10 monsters.
When DDO developers first play test DDO with casters; they assumed that spell points are infinite. That's probably why the casting monsters don't really have concentration or a mana bar. That's also probably why mana potions were originally sold in beta and back in the days when "The Twelve" was not opened and in a secret in game NPC store. Now that "The Twelve" is opened, the store has been removed.
My suggestion? Grant casters the ability to regenerate spell points to match the number of encounters (monsters) in the dungeon. Reduce the maximum spell points to may be to one-half or one-third of the current maximum amount; but possess the ability to regenerate spell points like may be default of 60 spell points per minute, or 1 spell point per second. Create items of spell point regeneration to make regeneration go faster. Remove all shrines (There are no shrines in PnP). Keep the current availability of spell points potions in AH and DDO store and the Eberron shards.
If spell points ran out; just tell party to "camp" for a couple of minutes to regenerate.
In the same token; for the melees that possess "regeneration" items can regenerate HPs as well and they can stop to quaff their potions instead of depending on the cleric. This also removes the need for dungeon alert and zerging. If party does not want to wait, the casters have the option to leave group and get partial XP or the melees (or ranged fighters with infinite arrows) can go ahead without arcane or divine caster support.