Here are the summary of changes in tram routes:

As of Sunday 11 December 2011, many of the TPG (public transportation in Geneva) lines will be changed. 

 The major change is with the re-organization of trams. In turn, some buses and trams will run on different routes and some will be cancelled. Please see the following summary for major lines (tram in blue and bus in black):

Lines that will no longer be in service:

13, 16, 17, 18, 20, 27

 Lines with modified routes:

1, 2, 3, 4, 5, 7, 9, 10, 14, 19, 21, 

 No change in the routes but with new timetable:

6, 8, 11, 12, 15, 22, 23, 28

 The Blandonnet stop will be served by tram 14 and buses 23, 28, 57 and Y.

here you find all changes per line in details:

http://www.tpg.ch/fr/horaires-et-reseau/horaires/changements-d-horaires/changement_ligne_11_decembre_2011.php

from my morning experience the "Nations" stop for the bus 22 has been moved to the stop "Nation" of the bus 8

The prices have gone up only for individual tickets. The monthly and yearly pass prices have not changed.

hmmmmm.... I don't now about that 'less congestion' remark... it has been horrible these days, with lots of buses and trams standing still... Last night it took me an hour and a half to get home, where earlier it would take 45 minutes to an hour. Not happy...

It is simplified for sure.

But I have also noticed that there are a lot more cars on roads and a lot more people in public transport than before. And this even at hours such as 10am which wasnt the case before!

The main problem for me is getting back home, I see huge crowds of people waiting for a tram that never arrives. I remember waiting 5 minutes for a tram and almost no one else waiting at the platform. Now there are maybe 30 people waiting and I had to wait 15 minutes.

My wifes commute home has now doubled in time also. Before what used to be a tram every 10 minutes now turns to 1 every 30 minutes. Her commutte to La Plaine from Plan Palais used to be 30 minutes its now over 1 hr 10 minutes, and the trams are overcrowded. Don't sound like an improvement to me. 

In my experience these new changes in the tpg is just worse than ever. The trams keep up the traffic everywhere(I used to queue around 10minutes to get out from my street and now it's between 30-40minutes) and it's true that there are loads of people at the stops(even after 10am). I was suspecting that will happen because is it really a good idea to take 4 tramlines out of the traffic and expecting better transportation with it? In the other hand it'd work perfectly if there are no cars in the town at all...

let us hope it is teething problems and things will get back to normal .. surely this situation is not permanent  ?

Thanks for Link Reka, was looking for that. So GVA came to a standstill last night, My wife ended up walking from Planpalais to cornavin station, trams were arriving 60minutes late on her line, and some never showed at all. So what was a 30 minute commute last thursday turned into a 2 hr commute this thursday..good job tpg! Great to see Genevas finest out helping with traffic congestion too, what's the point of public transport if it's going to get stuck behind traffic....crikey.....

Yesterday, it was the teachers strike. It is the reason of the mess. However, the new network is a disaster :) In Lausanne, when we made a change 3 years ago, no complains. Everything was better ... Here in Geneva, I can only see that I heard on the news that the management is going to be fired apparently... Not a surprise after such a mess !

There was supposed to be the Occupy movement as well, but many of my collegues went through the place there were going to be having their demonstrations, and did not see anything... but on the noticeboard of TPG it kept saying 'manifestations'. Where were those 'manifestations' then?

I really hope next week is going to be better. If not, I am going to ask my moneay back for my annual abonnement, and buy a scooter... :-(