Ellen, I'm copy/pasting a very recent response (with a few edits in italics) I'd provided for someone with similar questions. I'll include the text/website for the ferries as well just in case you're interested. The http://www.parconazionale5terre.it/Eindex.php website is the official site for the park:
"Luann, yes, two parts of the Blue Trail are closed or nearly so. The segment between Cornigilia and Manarola has been closed to landslide damage for some years now, and only a piece of the (very easy) segment between Manarola and Riomaggiore is open: it doesn't go all the way through so will require backtracking (unless they have it fully open by April, Ellen).
You can see which CT trails are closed here:
http://www.parconazionale5terre.it/Esentieri-outdoor.php
The 4 sections of the Blue are 592-1 (SVA2) - 592-4 (SVA2), and the closed sections are marked with a red and white circle. Clicking on any of the trail notations will bring up a more detailed description. A bit of good news here? They recently redid the entire park website, and FINALLY made all the info available in English! YAY!
Bill, to further answer your question, you will be able to hike between Corniglia to Vernazza, and Vernazza to Monterosso as long as the trails remain open. There is no ferry service to Corniglia, however, so you'd need to take a train from Manarola to that one unless taking a different trail route. Ferry or train is possible between Riomaggiore and Manarola."
This is the website for current ferry schedules and rates, although it will be updated after Sept 27th:
http://cms.cnpstudio.it/USER_CONTENT/49/pdf/tratte_pdf_eng_42.pdf?cache=956630,885601044
