Bear in mind that all those generations of the Snapdragon family, plus the Hummingbird and Apple's A4, are still based on ARM's Cortex-A8 architecture despite being heavily customized. Even the dual-core Snapdragons will be a rehash of Cortex-A8 with 45nm technology.
One of the current big players, which announced a Cortex-A9 chipset that will be available for smartphones, is Texas Instruments. TI's current A8-based OMAP3 family can be found in various phones running the gamut of mobile operating systems. Its most popular reincarnations are perhaps the Motorola DROID line, and the Nokia N-series. The new DROID X has an OMAP 3630 chipset inside, clocked at 1GHz and produced with 45nm technology. Power management of TI's current flagship seems to be outstanding given the DROID X's claimed 8 hrs of talk time.
The OMAP4 generation is where it gets really interesting, but we are yet to hear for a handset with these A9 chips to be announced. Cortex-A9 is a completely different animal, focusing on multiple core operation, dual-channel memory controller, efficient instruction handling up to the application level, and overall superior power management. OMAP4 should offer what dual-core Snapdragons do, plus even better battery life, universal hardware decoding for playing any media file you get to it, and TI's superior image processing and stabilization technologies.
The OMAP4 family, however, doesn't come with an integrated baseband modem as Qualcomm's Snapdragon solution. The TI dual-core OMAP4 chipset is also running at the slower 1GHz speed, but knowing how prone to overclocking the OMAP chips are, difference in raw speeds should be negligible. In fact, TI itself is listing the cores as 1GHz+.
There is another dual-core Cortex-A9 based smartphone SoC besides OMAP4, and from a very worthy contender. It is a creation of ST-Ericsson – a joint venture between Ericsson, whose wireless chips are found in more than half of the cell phones worldwide, and STMicroelectronics. The chipset is called U8500, supports up to 1.2GHz dual-core CPUs and, similarly to OMAP4, takes advantage of the rich SMP (Symmetric Multi-Processing) functionality that Cortex-A9 has to offer.