Rasmussen Reports polled the hypothetical three way matchup for Alaska Senate between Republican Joe Miller, Democrat Scott McAdams, and newly minted independent Lisa Murkowski.
This is clearly the best case scenario for Murkowski as she actually won't be on the ballot, but even in this case, the result is not changed from the previous poll.
Yes, Murkowski turns out not to hurt Miller a bit. In the last poll Miller led McAdams by 6. In this poll, he leads McAdams 42-25 (MoE 4.5) with Murkowski drawing 27.
The breakdown of the Murkowski entry: Miller loses 8 points, McAdams loses 19 points. Hmm, 19 + 8 = 27, the Murkowski figure, suggesting strongly that Murkowski is more attractive to Alaska Democrats than she is to Alaska Republicans, which obviously is not bad news for Joe Miller at all.
However this falls far short of the Connecticut situation, when Joe Lieberman was able to capture true dissatisfaction Republicans had with their own nominee's position on the War on Terror, allowing him to overtake the Democrat and win as the Connecticut for Lieberman candidate. And again, Lieberman was on the ballot. Murkowski is a write-in.
So the only apparent consequence of the Murkowski write-in run is to make Miller as secure in this seat as she herself was.