Looking ahead to Icecrown at trinkets, since they're always the most dynamic of gear choices, we have these two released so far. (They're not available on wowhead for quick links yet.)
10 man Muradin's Spyglass - Items - Sigrie
Equip: Improves critical strike rating by 131.
Equip: Each time you deal spell damage to an opponent, you gain 18 spell power for the next 10 sec, stacking up to 10 times.
25 man Dislodged Foreign Object - Items - Sigrie
Equip: Improves haste rating by 155.
Equip: Your harmful spells have a chance to increase your spell power by 105 and an additional 105 every 2.0 sec for 20 sec.
Looking from an Arcane perspective the latter almost has too much haste, while the former is a buffed Razorscale 10 trinket.
I find the haste trinket to be really great. If you could wear two of them, I'd agree that there's too much haste. However it says "Unique: Dislodged Foreign Object (1)" so I assume you'll only be able to wear it once (unlike for Reign which you can wear twice, once with an ilevel of 245 and once with an ilevel of 258). I know that the TotGC trinkets had those unique flags on the PTR as well but I assume they were removed because TotGC wasn't big enough to have two different trinkets of each type drop, which isn't the case with Icecrown.
The proc seems to be very strong, some napkin maths assuming the standard 45sec ICD and ~50 seconds between procs:
Average SP gain while proc active: (105+1050)/2=577.5
Average SP gain overall: 577.5*20/50=231
Using the same assumptions, Flare of the Heavens for example grants only 170 SP, 61 less than the Icecrown trinket.