I compiled this list of "lost" spell effects from the two previous TES:

Missing In Action:

(morrowind, not listing a few that really wouldnt fit anymore)
Mark/Recall
Levitation
Daedric/Divine Intervention
Extrication
Jump
Burst of Speed
Poison
Blind

(Oblivion - some of these are inexcusable, others are probably just as well left out)
Feather
Burden
Open Lock
Water Walking
Possibly Fire/Frost/Shock shield, depending on whether the "Cloak" destruction spells serve a similar function

Bound Armor
Summon 50 different things
(Soul trap is not on the list above but this cant possibly be missing, so Im not including it as missing)

Disintegrate WEAP/ARMOR
Damage health/fatigue/magicka
Drain health/fatigue/magicka
Weakness to xyz

Chameleon
Command Creature
Command Humanoid
Silence (New spell Muffle is a noise/sneak thing, so Silence is missing)

Dispel (might not be of much use with this system anyhow)
Reflect Damage
Reflect Spell
Spell Absorption

Absorb health/fatigue/magicka/skill
Fortify health/fatigue/magicka/skill
Resist XYZ

MODDERS OF THE NORTH! ON MY MARK! FIX IT!!!

Several of the removals I really approve of, though honestly my approval is more grounded in how Oblivion handled spells than anything else. There were many effects, you needed to have at least one spell with a given effect to make new spells, and there was no easy way to sort/remove spells (without mods). You ended up with a vast list of often poorly named spells that was a huge headache to navigate. I for one - despite being a die-hard mage player - will be glad to see that mess go. It got absolutely ridiculous once you started counting all the fortify/resist/weakness/absorb variants.

I really, really hope some spells can get added back into the game very quickly via mods - particularly mark/recall, open locks, and some form of jump/levitate/fly/movement sort of spell. I could care less about the various weakness/absorb/fortify/etc spells as they created too much class crossover (equivilant capability, re: open locks is fine for me, but actually enhancing skills you don't have? meh.) and were simply too awkward to manage. With the new magic system I can't see a good way to implement them practically either.

Chameleon I'm glad to see gone. I always appreciated that Invisibility allowed mages to move similarly stealth but differed in critical ways(particularly before the equivilant skills were very high, thus for the majority of the game); Chameleon was simply a silly trump card.

The limitations on conjured equipment are... well, I understand why (see comments re: too awkward to manage) but it seems very odd that there is no conjure mace at least, only edged weapons. I've never been a fan of the conjured gear spells personally though, so I don't really care. As with skill buffing, as a mage I always preferred to find other ways to deal with issues than hitting something with a weapon, be it conjured or otherwise.

Water walking is pretty surprising to me. I'm pretty much baffled why they removed it.

Finally, feather/burden: I'm very curious here (forgive my ignorance), but have they changed the way carry weight/inventory are managed that I've missed? Or did they feel that Feather became too much of a mandatory spell/enchant? Burden was pretty much useless unless at very high level (at which point you typically had better combat spells to cast).

My thoughts, anyways.