Looking at the bluray reviews for season 1 and 2, it looks like the general feeling I've seen lately that Enterprise is a lost "gem" seems to be spreading. The blurays are a big part of it.
I think the newly produced special features are a big part of it. Berman and especially Braga have used every opportunity in these documentaries to spin the tale as to why Enterprise was such a disappointment, not just critically but also creatively. Of course it had very little to do with them (although Braga does take some blame) but all to do with UPN and the studio. In light of these "revelations" reviewers and Trek fans seem to have become a lot more forgiving of the show's obvious shortcomings.
My opinion of the show hasn't changed. It's an okay show with some great episodes and some stupendously boring installments. Overal it's enjoyable but for various reasons it's still the worst of all Star Trek series.