I was in Lisbon last week for work, and since Thursday was a national holiday (April 25, day of the carnation revolution), the Via Lusitana organized an arrow painting party. I was so happy to participate and can tell you that the signage is tremendously improved south of Porto.
We were mainly near Alvaiazere, where the municipalities have installed the permanent blue and yellow markers on walls for a very long stretch, maybe almost 200 kms. More and more people in towns have heard of the Caminho and can help you out.
We spent some time in the eucalyptus forests where I got lost, and now even I would make it without a problem. We re-routed a short stretch where mean dogs had been a problem, and the added bonus was that it now goes through oak/cork rather than eucalyptus!
I know that it's a lonely camino, but going back through some of these little villages (and lovely towns, like Tomar) reminded me what made the Lisbon-Porto piece special for me. The people are just wonderful -- helpful and kind, I can't say it enough. The scenery isn't spectacular like the Salvador or the VAdiniense, but it is rural and green and out of the hustle and bustle.
And if you keep checking on the ViaLusitana's web page and the threads in this forum, you'll see that lots of new places are opening and more and more pilgrims are coming.