From Bailey v. Janssen Pharmaceutica, Inc., 2008 U.S. App. LEXIS 16042 (11th Cir. July 29, 2008):

The action was originally filed in state court and removed under 28 U.S.C. § 1441(a), pursuant to § 1446(b), by the last-served defendant more than thirty days after service on the other defendants. ***

This case presents an issue of first impression for the Court with regards to whether, in multi-defendant litigation, the limitations period for removal expires upon thirty days from service on the first-served or last-served defendant under 28 U.S.C. § 1446(b). For the reasons that follow, we adopt the so-called "last-served" defendant rule***.

On its face, § 1446(b) does not appear to address itself to multi-defendant litigation. *** In applying the statute to multi-defendant litigation, courts have split over whether each individual defendant has a right to seek removal within thirty days of receipt of service or whether the appropriate time window for § 1446(b) runs from receipt of service by the first-served defendant only—in other words, whether the "first-served" or "last-served" defendant triggers § 1446(b)'s limitations period. ***

First, we observe that the trend in recent case law favors the last-served defendant rule. *** Among the four courts of appeals that have considered this issue, only the Fifth Circuit and (seemingly) the Fourth Circuit 5 have adopted the first-served rule, and have held that a notice of removal is only timely if it is filed within thirty days of service of process on the first defendant. ***

Second, we are convinced that both common sense and considerations of equity favor the last-served defendant rule. The first-served rule has been criticized by other courts as being inequitable to later-served defendants who, through no fault of their own, might, by virtue of the first-served rule, lose their statutory right to seek removal. ***

Third, the Sixth Circuit recognized that the first-served rule requires reading first-served defendant into the statute, whereas the statute, as written, could reasonably be read to permit each defendant a right to remove within thirty days of service on the individual defendant***

Fourth, we are unpersuaded by the rationale behind the first-served rule. Those courts that have endorsed the first-served rule have generally done so for two reasons: (1) it is perceived as more consistent with the unanimity rule for notices of removal; and, (2) courts are to narrowly construe the removal statute and federal jurisdiction.

*** The last-served rule is not inconsistent with the rule of unanimity. Earlier-served defendants may chose to join in a later-served defendant's motion or not, therefore preserving the rule that a notice of removal must have the unanimous consent of the defendants. *** [W]e do not find that a strict construction of the removal statute necessarily compels us to endorse the first-served defendant rule in light of the Supreme Court's decision in Murphy Brothers, 526 U.S. at 347-48, 119 S. Ct. at 1325.

Finally, we agree with the Eighth Circuit in Marano that the Supreme Court's decision in Murphy Brothers supports endorsing the last-served rule. The court observed:

The [Supreme] Court [in Murphy Brothers] held that formal process is required, noting the difference between mere notice to a defendant and official service of process: "An individual or entity named as a defendant is not obliged to engage in litigation unless notified of the action, and brought under a court's authority, by formal process." Thus, a defendant is "required to take action" as a defendant — that is, bound by the thirty-day limit on removal — "only upon service of a summons or other authority-asserting measure stating the time within which the party served must appear and defend." The Court essentially acknowledged the significance of formal service to the judicial process, most notably the importance of service in the context of the time limits on removal . . . .

Marano, 254 F.3d at 756 (internal citations omitted).

The case usefully collects the authorities on the issue as of July 29, 2008.