According to the chaps at Phandroid, the brilliantly named Garfield Brusewitz of Sony Ericsson said, "We expect initially to focus on products in the higher segment, but later on we will also supplement with products for the broad mass market. The first Android phone from Sony Ericsson is expected to show up for the summer."
That means we're almost certain to see something along of the lines of the stonking Xperia X1 packing Google's mobile OS. Either way, it'll be an Android smartphone that should surely eclipse the T–Mobile G1.
On top of that, HTC has also said that it will be working on new Android phones next year. Having built the G1, there's a good chance that this could be another joint effort with T–Mobile.
We'll be keeping our ears to the ground for more new Android phone news, so keep it here for news as we get it. For more Android goodies, check out our hands–on video of the T–Mobile G1.