Nope... RoL is a completely different game.
Rise of Legends wasn't as highly rated as Rise of Nations, but I suppose it's more a question of taste. I've played both, so here's my comparison:
Rise of Nations
An interesting combination of Turn-Based and Real Time Strategy (think Civilization + Age of Empires). While a single game can span from B.C.E. to now, you have the option of confining the timeline to specific periods. Units cover all domains (Land, Sea and Air) and there are a few specialty units, i.e. spies and generals (Don't get excited, though; using them to maximum ability involves significant micromanagement). It's fun, easy to get the hang of, and the map editor is competent. You can even create complex scenarios if you can figure out the game's scripting.
Overall, I recommend this. It's addictive and versatile. If you buy the expansion pack, you'll also be able to play a number of creative and original scenarios available on the Net.
Rise of Legends
It doesn't share a lot of similarities with RoN, and is straight RTS. There are only three sides to choose from, although each is significantly diverse from the others. Single Player mode is primarily story-driven (although I have the Russian version of the game, so I missed all the important cutscenes). I was quite disappointed to find there are few opportunities in the campaign to compare the different sides' abilities, and there are no naval units (in fact, no water terrain) at all. Technology is somewhat similar to RoN, although there isn't anything major like changing ages.
RoL is interesting; not, in my opinion, as good as RoN, but still enjoyable. If you like Science Fiction and Fantasy, you might like this.