Tokyo area trains are running on a normal or near-normal basis.

JR East has still not uploaded the latest timetable to their official 
Narita Express English language pages.  Use their Japanese timetable:
http://www.jreast.co.jp/railway/pdf/nex_timetable.pdf

Rail services in Tokyo area, updated April 6:
http://www46.atwiki.jp/earthquakeinfo_en/pages/40.html
(Narita Express departures at Tokyo, Shinjuku and Yokohama also in this 
page)

---

Most rail companies are running on special timetables.  Internet 
timetable query systems do not know about the modifications.  Query 
systems on official pages of railroad companies may also be inaccurate.

As for JR East, they have neither modified their English-language 
timetable pages, nor put up a notice stating that they are defunct.

---

JR Central will resume to normal operations during peak from April 7. 
Daytime runs will be reduced to about 80% normal.

Joban Line Katsuta - Hitachi - Takahagi and Mito Line opens tomorrow 
(April 7).  Tohoku Line (local line) Fukushima - Kouriyama also opens 
tomorrow.  Tohoku Shinkansen Ichinoseki - Morioka will open tomorrow 
afternoon.

Nambu Line rapid service will commence April 9.