This topic has been discussed before by people with a lot more experience than me. Do a search of the forum, and I'm sure you'll find it. As I recall the gist of the discussion was that prior time makes you more comfortable in the aircraft, but you still have to learn to do it the "Navy way". In the beginning those with prior flight time may do a little better, but this evens itself out in a few flights. There does not seem to be a correlation between prior flight time and final NSS, hence no connection between prior flight time and selection of "jets". IPs do expect a little more from you depending on how much flight time you have. You also may be a candidate for an accelerated program (also discussed previously). I think the general consensus is if you want to get flight time and can afford it - go for it and have fun. If you can't, don't worry about it. You have just as much a shot at success at Primary as someone with flight hours.
Personally, I've seen it go both ways. I know two commercial pilots that have entered Primary in the last year. One completed Primary with an NSS of 74 (perfect is 80) and selected helos (his first choice). The other DOR'ed. Go figure.
Does everyone want to go Hornets? No. A lot of guys really want helos or P-3s. One of my girlfriends is holding out for Tomcats. There are, however, a fair number of people who want jets and it is still very competative to get them. The good news is the number of people who want jets at the beginning of Primary is much greater than the number that actually list TACAIR as their first choice on selection day. Many people realize that jets are not their cup of tea by selection. This may be for personal reasons, not having "jet grades", or simply not enjoying PAs or going like a bat outta hell. Only experience in the airplane, and exposure to the various communities teach you these things. For instance, I am "die-hard, tunnel-vision, gotta-get-jets", but I'm well aware that this could easily change during Primary, or be changed for me if I don't make the grades. I hope this long-winded explanation helps. Those of you more in the know - Matt, John, Mari, Jack, etc. please feel free to jump on in.