The political actors move on three layers, which serve three purposes:
1) Mobilization
2) Formation of opinion
3) Implementation

The political mobilization happens on large public social networks - in Switzerland mainly on Facebook. There is an increasing number of groups and sites with political content already. 
Also, the profiles and pages of politicians play an increasing role. Not only as information channels, but also for direct interaction with the voters. 
There are other platforms too, but they play a minor role to date: Twitter has gained popularity as a political instrument, when Barak Obama started to campaign on it - In Switzerland, the Twitter community is still small and not yet a mass medium in the political process - but this can quickly change, if an important politician starts to actively use Twitter for his campaign. Until then Twitter is important mainly to address a segment of Key Opinion Leaders.
I expect more variety of platforms for this first layer, but probably most of them closely linked and integrated with Facebook and / or Twitter.

The second layer is used for the formation of political opinions. It has a smaller user group: the politically interested and the political opinion leaders.Web Tools used today in this layer are primarily discussion forums with a political focus: Some are operated by parties, others are independent. I expect in the future primarily independent platforms for this second layer: The politically interested want an open, broad debate and no "propaganda".And it is increasingly possible on social platforms today, to filter the information flows according to preferences ('Follow'), across all party boarders.
The tools will change significantly in this area with the possibilities of web 2.0.In Switzerland, politnetz.ch is a good example showing the direction political web 2.0 tools may take:
 - Strong integration with the first layer of mobilization (Facebook & Twitter) - Resulting in a broad political discussion. 
- Not just content, but people: The social web is all about people, profiles, connections, friendships etc
- Enhanced functions to collectively form & express opinions: The "I Like" of Facebook is available for comments, as well as for people (political Support)
An integration with the third layer is however still missing.

In the third layer of implementing the political programs very little happens today on the web. There are a few approaches and experiments, as the Green Liberal Idea Pool of the section Kloten (Implemented on Colayer ). Partly open to the public, the main focus of the platform is, to facilitate the political process of discussion, coordination and implementation with virtual spaces and tools.  
One exception is the small Swiss Pirate Party. The web is used not just for information, but also most parts of the mobilization and implementation happens online.Various tools are used for this: In addition to a website and a newsletter:
- A forum for broad discussion, as well as to coordinate and support the implementation. 
- A wiki page for term definitions. 
- IRC and Mumble for real time.

Surprising actually, that Swiss politics hasn't yet discovered the Web for more activities. In Switzerland, most of the politicians are not full time, and Web 2.0 & Social Tools could play an important role supporting them - in the mobilization and in political discourse, as well as more and more in the implementation too.