OP I wouldn't aim for that 25% just yet.
From their own website, EJ still has this:
"Since HST and HTT extra ticks are for the most part dependent on your latency their first breakpoint of 3764(3306 for goblins) is greatly devalued."
Thus, I wouldn't necessarily recommend going for the HST haste point.
Most shaman at lower gear levels will go for 12.51% raid-buffed haste (thats ELW+1). This is 871 haste if you are spec'd into NS, or about 3040 if not spec'd into it (assuming a 5% haste buff in raid).
It is very hard to reforge down to 871 haste, thus you will often find yourself with an abundance of haste which isn't always useless but you won't be at any special breakpoint (like you said you are basically 2000-2100 haste away from the next breakpoint which is nothing stellar (riptide +2)).
Disregarding the instant cast portion of NS (i will get to that later, but it is EXTREMELY good), at this point you might want to consider using EM, especially if you are good at using and tracking cooldowns.
Right now I am spec'd into EM, but I change depending on the fight (have not gotten to go into ToT that much yet but I already know when I would change and for what fights. generally, if there is no stack up phase for healing rain I don't use EM).
If you elect to go for EM, get to 9.88% haste UNBUFFED (remember you will not get 5% free haste since you wont have NS). This breakpoint corresponds roughly to ~4200 haste (its not on EJ at least when I last checked).
What this does is give you a +3 HR (as opposed to a normal +1) whenever you cast EM. Thus you can an extra 4 ticks essentially of healing rain whenever you use EM if you get to this breakpoint (assuming the 5% raid buff).
Now, this isn't useful on every fight. Obviously any fight where there are set phases where you stack up and need massive heals such as healing rain (tortos stomp every ~40-45 seconds = EM every other one, maegera = EM every other one), it truly shines.
At the same time, the instant cast portion of NS is extremely good. Any fight where you don't get to abuse healing rain, OR where there is an alternative mechanic where you still need big and fast single target heals, you should spec it and reforge appropriately (you will probably have an overabundance of haste even when reforging unless if you manage to hit riptide +2 which again isn't super stellar).
For instance, I can make the same argument that NS is just AS good as EM for maegera due to the fact that the fire debuff can get insanely irritating late into the fight and rapid heals are required if that person is at the wrong place, etc.
Of course if you don't like tracking cooldowns or a lot of reforging, then just stick with NS and at this point don't worry about too much haste. later on you can get up to that riptide +2 or even healing rain +2 (that would be ANOTHER 2000 or so haste which is a lot to pour into one stat).