GSMA Mobile World Congress (formerly 3GSM World Congress) is without a doubt the most significant trade show/exhibition/gathering for 3GPP-based systems (GSM, GPRS, EDGE, WCDMA, HSPA, and LTE). During this gathering, there will a flurry of announcements and I expect a lot of LTE progress announcements as well. Stay tuned.
The press conference schedule is at http://www.mobileworldcongress.com/pdf/press_conference_schedules.pdf. Also, Unstrung has a pretty good coverage of the show at http://www.lightreading.com/gsma/.