Is it really safe to eat sushi?

As safe as it is to eat rare or medium-rare steak.

Mmmm...... sushi...

what do you think would be unsafe about it??

I eat sushi a lot (often once a week, more sometimes) and have for years. I have yet to have gotten sick from it. I do not know anyone that has gotten sick from eating sushi either (and I know a lot of people that eat sushi regularly). If you feel uncomfortable, but want to try it, stick to the most popular and busiest sushi places in your town. Also, look for reviews online and in local publications.
Unfortunately, "sushi-grade" meat is not FDA regulated yet. What "sushi-grade" means is that it has been frozen a specific amount of time to kill off any parasites that might have been in the meat. So, if that doesn't scare you off, just stick to popular restaurants/sushi bars.
Oh, and it's not comparable to eating raw steak (which you should NOT eat--rare ok, raw no way!!).

Sushi is safe, but I tend to stay away from low-end, cafeteria-style sushi places. The NY Times had an editorial on 7/15/07 that you might find informative. Here's a good quote:

"If you take raw and partly cooked shellfish out of the equation, the risk of falling ill from eating seafood is 1 in 2 million servings, the government calculated some years back; by comparison, the risk from eating chicken is 1 in 25,000. (Over all, 76 million cases of food poisoning are reported a year.)"

Raw shellfish (e.g. oysters and clams) are the risk -- NOT the raw fish normally used in sushi. The only risk associated with properly-prepared sushi comes from high mercury levels found in some fish (e.g. swordfish and tuna). Of course, cooking those fish doesn't make the mercury any better for you.

There was also a piece some time ago where they mentioned that virtually every piece of sushi that's served in the US actually goes through a deep, deep freeze before it hits your plate. This effectively kills all the bacteria that might have been in the fish before.

according to research some are less safe. Salmon spends some life in freshwater fresh water fish have more parasites

You are not likely to get food poisoning from sushi, but if you are a woman of childbearing age, you might want to stay away from tuna and other fish that are high in mercury content (especially dangerous to a developing fetus, where it can cause developmental problems). To find out more about mercury in fish, you can check out: http://www.sierraclub.org/mercury
eating tuna a couple times a month is more or less okay, but more than that might pose a problem. On the Sierra Club site you can also order a testing kit to send in a sample of your hair to a lab that will tell you if you have high mercury levels in your body.

we don't freeze fish, I own 2 sushi bars and we fly our fish in fresh 2-3 times a week. As a trained chef we look for parasites as well as our suppliers. Its our job to serve you fresh not frozen sushi. The exception to that is some albacore and some salmon.

Sushi is rice with vinegar in it, so yes sushi is safe. Sushi doesn’t inherently mean fish.
If you are eating raw fish in the states at a decent restaurant, there are health codes in place to make sure you are reasonably safe. People sue folks for just about anything, so most places dot their i’s and cross their t’s.
I would worry more over the burgers out there.