Turbine have tried to extend DDO's use-by date by simplistically increasing the level cap. This is quite simply the wrong way to go. Increasing the level cap leads to inflation, and we can see this already.
Top level bosses already have absolutely ridiculous HP totals, and I'm sure by level 30 epic elite we'll be hitting bosses with seven digit HP numbers. Bigger numbers does not equate to cooler it just makes killing things insufferably tedious.
Peoples' carefully farmed snicker-snees and gew-gaws are now worthless junk compared to random trash. So all of the hard work people put in has now been completely undermined.
What do I think they should do instead?
The stand out strength of DDO for my money is TRing and I think that more effort should go into encouraging TRing. You get past life feats, and wonderful they are. You can get completionist and that's extra cool too.
But there are so many other variants:
Rewards for different lives with different races (corresponding completionist).
Access to PC races or Prestige Classes that have TR prerequisites (this would involve actual honest to goodness prestige classes, not an enhancement based kludge)
Prestige Class/Race past-life feats.
Items with neat extra abilities that are unlocked by past-life feats or that receive an increment every time they get put into a TR bank.
In short, rather than constantly moving the finishing line further and further away, stick with what you've got and make it richer and broader.