Dan Block (whom I have high hopes of doing my Ph.D. studies under) has beaten me to the punch. He has not only written several articles (JETS 32, 1989; SBJT 1.1 Spring 1997) where he articulates the theology of the Spirit in the Old Testament and its correlation to the New Testament, but has also included an excursus in his magisterial two-volume commentary on Ezekiel (NICOT Chapters 25-48 pp.360-1) on this topic. A topic which I still hope to work on as part of my Ph.D. dissertation (tentatively titled "A Theology of the Spirit in the Former Prophets").
And his conclusion is much as mine...the disjunction between the two testaments and the person and work of the Spirit (as has popularly been believed) fails to grapple with the actual evidence of the text. The Spirit indwelt believers in the OT in much the same manner as the NT, but in the NT this was unbounded by ethnicity and status. In both testaments the Spirit endows with power for service. In both, there is an "ecclessiological continuity" (NICOT 360) as evidenced by the requirement for Israel to have circumcised hearts (Deut. 10:16; 30:6; Jer. 4:4) that would require the indwelling of the Spirit for sanctifying transformation (Eze.11:19; 36:26). In both, the Spirit is essential for hope of salvation (Ps.51:10-11).
As Block notes in his conclusion, "Ezekiel anticipates the day when the boundaries of physical Israel will finally be coterminous with the borders of the spiritual people of God. But, as [Eze.] 37:1-14 will demonstrate, this can be achieved only through direct divine intervention, Yahweh's infusion of his people with life" (NICOT 361).