@ Miiyaa -
Established official lore states that Tyrande and Malfurion are 10,000+ years old. It also states in one of the novels (I think was referenced above?) that they are starting to feel the effects of age, so... my personal take on it is that A) Wikis are unreliable source material. Definitely use them, but keep that in the back of your mind. B) There is no official guidance on how the Kaldorei have handled the 10-15 years since the loss of their immortality in regards to aging.
My headcanon is below, take or leave. :)
Night elves, once they began living near the Well, gained immortality due to the magic in the area (Sourced from a Wiki, but it makes sense. Kinda like radiation). The symptoms or signs of aging on the body are A) the effects of experience (many years of laughing/frowning/being in the elements/hard labor, etc) and B) the body's ability to regenerate itself on a cellular level.
If we can accept that immortality simply means that cells continue to replenish themselves with no deterioration in quality, then we have a race that does not physically age, and does not suffer from illnesses related to age... but is still vulnerable to disease and death by violent means.
This means we have a lot of Kaldorei wandering around that have seen a whooole lotta turns around the sun, as it were. Because even though the race has seen a lot of conflict, they haven't seen enough warfare to experience the sort of population decimation as, say, the draenei.
The events in Hyjal were... what? 10 years ago? 15? Less than half a century. So we have these incredibly old elves that are suddenly cut off from the magical radiation that has given them their immortality. So now they are suseptible to aging.
But we have an example of what sort of lifespans they can expect without the Well- the Highbourne that went to the Eastern Kingdoms and became the Blood Elves. The blood elves have been separated from the Well of Eternity for thousands of years, and are still a rather long-lived race (The chart you listed, in fact, seems in line with Blood Elf lifespans, in my opinion).
So- The Kaldorei could feasibly still live another 3-4-500 years before they succumb to age.
I also really like some of the ideas expressed above regarding their development. If you're trying to figure out the age of your Kaldorei, I think it's reasonable to say that 100-150 is young adult, with full maturity (as deemed by the culture in peace times) around 200. That was the culturally accepted norm BEFORE all the recent conflicts. Your elf would reach physical maturity far far earlier, but just as we see signs of physical maturity at young ages in children (menstration in young women, voices changing in males, etc), the young ones are not considered mature by our culture until 18, 21, or some other age accepted by the society.
So an elf may reach physical maturity around 20-25, but not considered an adult- trusted to make decisions without guidance, until far later. I have some ideas bouncing around in my head regarding female Kaldorei tattoos and this system of maturity and aging, but it's not fully baked yet. >.>
All in all... I don't really think there's many wrong answers, unless you're saying your night elf is a mature adult and was born on Teldrassil. But I feel that's a sign of 'new to roleplaying and don't know where to find Lore resources' than anything else.
Edit: Discussed with my far more lore-knowledgeable RP partner, and I was reminded that Nordrassil, once it was formed, was blessed by Ysera, Alexstraza and Nozdormu. Nozdormu's contribution was the gift of immortality to the night elves.
When Teldrassil was formed after Nordrassil's destruction, Nozdormu refused to bless it again- it only received blessings from Alex and Ysera.
Now that Nordrassil has been replenished... it is the thought that Nozdormu lacks the power to bless it again - Which makes sense if you consider that it was reformed after the Cataclsym, and once Deathwing was dealt with, the dragon aspects were stripped of much of their power.
So I guess that answers the question of whether they regained their immortality. :(
Edited by Sihai on 4/26/2013 10:57 AM PDT