One of the best analysts of radical Islamist movements, Stephane Lacroix, has produced a new paper for the Brookings Doha Center, "Sheikhs and Politicians: Inside the New Egyptian Salafism," which is worth your attention. An excerpt from the summary:
The rise of political Salafism has reshaped the Egyptian political scene. Though the Muslim Brotherhood still occupies the dominant position, it has lost its hegemony over Islamist politics. The relationship between Salafis and the Brotherhood has evolved since the revolution, from discrete cooperation to fierce competition. The final outcome of this competition remains uncertain. It could end up pushing the Salafis to a more intransigent stance intended to distinguish them from the “responsible” and “pragmatic” Brotherhood. Alternatively, it could convince the Salafis to fully embrace a more pragmatic politics themselves. This question is also closely related to that of the relationship between the Nour Party and its parent movement, the Salafi Da’wa. To what extent will the party manage to assert its political independence?Information page at the link above. Direct links to the PDF report in English here; or in Arabic here.