The International Greek New Testament Project appears to be making good progress in its production of material on the Gospel of John. Last week I was out in Salzburg for some of an IGNTP colloquium hosted by Prof. Karlheinz Schüssler.
Particular things to note:
All Gordon Fee's 20,000 cards of patristic citations have been transcribed.
An edition of all the majuscule mss of John should be out by the autumn.
All the continuous Sahidic mss of John have now been transcribed.
The electronic edition of the Old Latin mss of John is now in prototype.