Not the fastest memory around, and probably not an enthusiast favorite. But I suppose for upgrading prebuild mashines, or buying new prebuilt mashines it's a good thing. Dell, hp etc. don't really offer running memory at high speeds anyway.
With moderately high DDR3 ram pricing right now, I'd go for it if I was building an i7 machine. The difference is not that noticeable between DDR3 memory speeds yet, and today's computers are generally fast enough for home use. If you're building a Core i7 instead of taking advantage of cheap Core 2 Duos, you likely plan to upgrade components later on or you don't game. If you plan on upgrading, why bother buying super costly ram and overclocking if it's only temporary? If OCing is pure hobby for you, then you'll splurge anyway and won't want this. But if you plan to upgrade, why not wait until faster speed DDR3 prices are lower? This is a fantastic grab for cash savvy people wanting to get their hands on an x58 mobo for use with a better processor later on. You can always dump this ram into that "slow" Core 2 Duo HTPC later on when your DDR2 mobo dies.