Here's the 00z ETA valid at 12z Wed:

Now the 12z valid at the same time:

The trough is definitely taking on more of a negative tilt and there is more phasing. The 54hr 500mb map shows a closed low taking shape around the Delmarva, but of course by this point it's a little too late:

I'd like to see some input from the pro's here... what do these changes mean? Obviously the current ETA solution is unfavorable, but could this difference in the 500mb features be a trend towards a more favorable solution?