I went back to TLP on the weekend, at least in part from reading posts from returning players wondering if it was "too late" to go there.
Luclin is open. I had logged in a character to see how long a trek via the spires to get to the (hopefully) better xp hunting grounds. For my Kunark warrior the trip is ridiculous so I gave up on that idea. My erudite cleric is now on the moon though. Baz had about 50 traders in it. Prices were decent (but plat is harder to earn so...).
I decided to do two firsts: I rolled a Vah Shir and made it a shaman. I know shaman is slow-play levelable solo (having been guilded with some hardcore slowplayers in the past) so better suited to the odd xp caps on TLP (vs. necro that loses most of the advantage of being able to solo reds due to the limits).
I knew I also needed to do something fresh class-wise to have any hope of sticking with it (I don't have a decent shammy alt on any server. One of the few classes I can say that for).
I also wanted to take advantage of Shar Val and adjacent zones. I'd rather be a frog but that's not an option at the moment.
I got to level 4 in the time it took my other TLP characters to get to level 2 (Shar Val pit is an indoor zone...).
In conclusion: not too late for TLP. If the slow xp turned you off already, it might be worth getting a character to Luclin (or going Vah Shir) as the XP is much better.