That is maybe something new a rumored devices goes against another rumored one. TechCrunch reports that one of their sources told them about a new Palm smartphone that would be released in fall.
Update: Rumor intensived very quickly and now we look at an ultra-thin Palm Eos.

The new Palm Pre like device would be smaller, but still run webOS. A smaller iPhone was also already rumored before the first iPhone actually started to ship. The iPhone nano is after two years still a far fetch rumor.
If the Palm Mini-Pre will have the same fate remains to be seen.
The latest rumors on when the Palm Pre actually will be released point towards early June, awfully close to the Apple WWDC 2009 conference where we expect to get exposed to the new iPhone 2009.
I do not think that this would be a smart move by Palm. The should have released the Palm Pre actually by now as earlier rumors indicated.