There are several regular (usually weekly) seminars that occur in the CSE department. They are subject-based collections of talks, in addition to the "special" talks and seminars by guests, visiting lecturers, VIPS, or students doing practice talks.
The "big" ones which discuss local UCSD work are:
AI_Research_Seminar (CSE259)
SysLunch (CSE229A) on Wednesdays and Systems Seminar (CSE294) on Fridays
DataBase Seminar (CSE239A)
Browsing through the course catalog you'll also see courses like the following, which discuss general work done in the field recently:
CSE252C, Select Topic/Vision & Learning
- CSE290's, Various seminars: Databases, Graphics, Bioinformatics, etc
CSE291's, Various seminars: Architecture, Unsupervised learning, IT & public policy, Systems & Networking