Swisscom starts with HSDPA or 3.5G (High-Speed Downlink Packet Access) at the end of April. With HSDPA, one should get at best 1,8 Megabit per second (Mbit/s). According to Tages-Anzeiger this is almost what you get today with fix line ADSL. In comparison, UMTS offers at maximum 384 Kilobits/s.

Orange wants also to introduce HSDPA this year, whereas Sunrise tests HSDPA in Zurich during the second quarter of this year and will then decide upon introducing it.

As for the data charges, Swisscom writes:

Swisscom Mobile is introducing a tariff option based on CHF 5 per hour with no turnover minimum. [...] Occasional users can also opt for a time-based tariff of CHF 39 per month including 12 hours of Mobile Unlimited usage, while frequent users will benefit from a flat rate of CHF 79 per month that includes 2 Gigabytes. These tariffs will come into force on 1 June.

See also (in german):
NZZ: Swisscom Mobile lanciert neues Hochgeschwindigkeitsnetz
Das UMTS-Netz gibt Gas