Sega Superstars Tennis will be out in 2 weeks in Europe and in USA on all major hardware, except PSP.

PS3 and 360 will have improved graphics and online.

Wii will have play with Wiimote (No online due to time constraints) and maybe cheaper

DS will have play with Stylus and will be the only handled version (No online due to time constraints)

On which hardware will the game sells best in your opinon and why ?

I think the game will sell better on Wii, because it's a game appeling to a very large audience. Also, all Sega's games seems to perform very well on Wii when they include... Sonic !

I would put DS version in second.

Then 360 version in 3rd for USA, PS3 version in 3rd for Europe.

What do you guys think ?

Wii version--nothing with Sonic in the name sells on anything but Nintendo, and M&S is selling better on Wii than DS.

I agree. Do you think it's why they didn't take time to input online ?

Or did they want to try to sell it also on PS3/360 thanks to this ?

Wii version - one of the first serious tennis games on the Wii (unlike Wii Sports) but Mario Tennis should be better

I would have to go with Wii>DS>360>PS3
sonic games sell better on the wii and DS

Wii, DS, PS2 and the other two (with no order)

I even thought about Wii, PS2, DS, but I'll stay with my first option :P 

is there a PS2 version ? I didn't even realised !

Wii

Wii, purely because mario & sonic was huge on the wii. Its raised sonic and sega awareness. Hell, even Sonic and the Secret Rings has started selling more since M&S came out.

^ That's a good point.

http://vgchartz.com/swlaunch.php?reg1=All&game1=Sonic+and+the+Secret+Rings+-+Wii&reg2=All&game2=&reg3=All&game3=&weeks=100&weekly=1

Mario and Sonic launched about 15 weeks ago, at that time S and the SR averaged 11K, now it averages 16ish K, in a slower period. M & S boosted S & SR with more than 50%