For many in biblical studies and archaeology, the excavations of the past half century in Jerusalem and the City of David, leading up and including Eilat Mazar's work, have been a surprise. Few thought, especially once Shiloh's excavations were completed, that much more could turn up. Jerusalem, unlike other sites in Israel and Palestine, is not the most archaeologically friendly site. Two significant problems are that the site remains an active urban center and it is not a traditional tell.
With respect to the former, this has meant that the site has been excavated in small, disparate areas throughout the city rather than a systematic way like one finds, e.g., at Megiddo. Also, some older excavations simply burrowed tunnels underground, a highly disruptive method that, among other things, disturbs the strata by overturning pottery and, in some cases, may have cut right through important structural elements.
With respect to the latter, builders on the summit of the City of David did not simply build over previous settlement layers but actually destroyed and uprooted those settlements to construct new buildings on bedrock. Consequently, as both Shiloh and Kenyon discovered, many sites on the summit have no occupation layers below even the Byzantine period, never mind the early Roman and Hellenistic periods or the OT periods.
At least in part because of these two problems, many excavators, by necessity as well as design, have focused on the slopes of the City of David where the occupational layers are more clearly evident. Interestingly, Mazar's exacavations are located in the same area as previous excavations carried out by Macalister and Duncan at the turn of the 20th century and Kenyon's excavations in the 1960s. I will try to update this post with a picture/map that shows the general area of her excavation. In any case, this means that much of the area she is excavating has been subjected to some of the disruptive methods of an earlier era in archaeology, which must make developing clear stratigraphic relationships, based on the pottery, exceedingly difficult. This complication, and the fact that there is no floor to connect the excavated walls that have been tentatively called David's palace, should encourage caution. What's more, so far as I understand it, the Phoenician-style is not a persuasive typological indicator as this style persists both before and after the date Mazar assigns to her walls; and, the pilaster capital that Kenyon discovered, which is being used to corroborate the date of this building, belonged, according to Kenyon's hypothesis, to a building of the Iron II period. Consequently, none of the evidence so far presented provides a compelling reason to accept Mazar's date, though the collective weight of some of the offered details does seem to support it. For a more certain conclusion, however, scholars will certainly need to see detailed reports, figures, and drawings of the excavated area and a comprehensive ceramics report.
One of the fundamental problems that will no doubt take on increased importance because of Mazar's discovery is the date of the stepped rampart leading up to it. For many years now, a debate has raged among archaeologists of Jerusalem concerning this rampart and, more generally, whether or not the fortifications of the Middle-Bronze Age persisted into Iron I. Along with others, Jane Cahill, a site supervisor on the Shiloh excavations, argues that they did while archaeologists such as Ussishkin and Killebrew have argued against this idea. For more on that debate, I refer you to their respective articles in Jerusalem in Bible and Archaeology: The First Temple Period.
In sum, I'm looking forward to hearing more about Eilat Mazar's discovery. I'm also looking forward to the work of Margareet Steiner, who is publishing and re-evaluating Kenyon's excavations, and I'm interested in the completion of the Qedem series on Shiloh's excavations. Finally, I'd like to see a professional re-evaluation of several early 20th century excavations in Jerusalem by Macalister and Duncan, Crowfoot and Fitzgerald, Weill, Vincent, and others. Scholars will need all of this work in order to make progress on the problems and controversies about tenth century Jerusalem.