I'm another university graduate (and post-grad with an Masters degree) who really likes the name Ella.
It was on our list for DD1. And, contrary to what has been posted by some, it is a name in it's own right and has rather lovely meanings, depending on where is cited as the country of origin. I know in German it comes from a word which means 'all, everything, complete' (can't think of the German word off the top of my head) and in Old English (I think) it means 'beautiful fairy maiden; beauty bestowed by fairies as a birth gift.' I know that the name has been around in England since the 11th Cetury, so ... Yes, it's popular but it has a long history: as names that are generally considerd to be nice tend to do!
I have a friend with an Ella and she is NNed 'Elle' and 'Elles'. Other friends of ours comment to her about how cool 'Elle' will sound when she's in her teens. I'm inclined to agree!
So, yes it is popular, but if you like it, to heck with people's very rude responses. It's not like you're wanting to call her Princess Tiamii, is it?
Which brings me to another point: just what do people want, anyway? A nice name that the baby can grow happily into a woman from (such as Jessica, Mia, Libby, etc) or some desperately trying-too-hard-to-be-different name?
Ah, and on the cool stakes - Ella Fitzgerald, anyone?