[I]f the election reflected recent state polls the probability of a Kerry win would be 98%. With 95% confidence I predict between 270 and 322 electoral votes.

This comports well with the projections of the sites in the post below, I think.

On another site, the preliminary findings of the meta-analysis are reported (and "mindgeek" turns out to be, apparently, Prof. Sam Wang of Princeton):

This calculation is a snapshot in time. It takes a large number of state polls and calculates the likeliest number of electoral votes if the election were held today and reflected those polls.

Results as of Sunday, July 18, 2004 based on state polls:

The current probability of a Kerry win is 98 percent. Counting only the last three polls the probability is nearly 100 percent.

270 electoral votes (EV) are needed to win. The current 50th percentile outcome for Kerry is 296 EV. The 95 percent confidence band is 270-322 EV.

Current probabilities by state (rounded to the nearest percentage point): AR 15, AZ 0, FL 98, IA 100, ME 98, MI 100, MN 100, MO 11, NV 25, NH 96, NM 100, OH 26, OR 100, PA 89, WA 100, WV 18, WI 88. The calculation is currently dominated by the large states FL (98%), PA (89%), and OH (26%). In most high-likelihood scenarios, two of these are needed to get over 270 EV. (my earlier posting left out PA)

Added comment: the current snapshot suggests that the threshold state is PA, where Kerry leads in 11 of the last 12 reputable polls since May 1.

There is a rank ordering effect, in the sense that states tend to move together. The rank order among big swing states is currently
D <-- MN - MI - FL - PA - WI - OH - MO --> R

[...]

Certain Kerry wins: IA MI MN NM OR WA
Likely Kerry wins: FL ME NH PA WI
Certain or likely Bush wins: AR AZ MO NV OH WV

All of this is quite in line with my own observations. Despite the possibility raised by some methodologies that Missouri may be moving Kerry's way, I really don't see any indication of that in any of the polls, and Ohio is still annoyingly unstable and confounding: an apparent trend toward Kerry some weeks back turned out to be very temporary, and yet it won't settle down to be firmly in Bush's column either, which I why I've go it (with West Virginia) as a toss-up.

On dKos, mindgeek writes "My analysis currently indicates that to win the election, Kerry must win Florida or Ohio," quite close to my own conclusion, which is that Kerry or Bush to win must get two of these states: Pennsylvania, Florida or Ohio. However, PA seems pretty firmly in Kerry's hands right now (his leads there in both the latest Quinnipiac and Zogby polls are outside the margin of error), so it comes down, as Professor Wang says, to Florida and Ohio. Since Ohio is mushy, Florida looks like the best bet at the moment (and Kerry's showing in polls there has been good lately, including an outside-the-margin lead on Zogby), but Florida is also enemy territory, obviously easily subject to manipulation by the Bushes, so I'd be much happier if we saw some positive movement in Ohio (also Republican-controlled, but not directly by the Bushes) and were able to take the onus off of Florida.