Back around the year 2000, it really seemed things in eastern Europe were all moving in the right direction. The entire region was becoming more and more democratic, relations were warming up. Prosperity in Russia was increasing, things in general were looking positive.
It wasn't seriously discussed, and no concrete steps were taken, but there was speculation that Russia might join NATO eventually. There was concern about China (concern which has proved well founded) and having another strong partner in Russia would strengthen the bulwark against them.
But, well, should we really have expected so much from a former KGB officer like Putin? No, he turned into another Russian strongman, seeking only to enrich himself, and determined to only leave power feet-first. He illegally coerced the Russian oligarchs into giving him billions of dollars.
The story of democracy isn't over in the rest of eastern Europe (heck, it isn't over in the USA!), and there have been various partial successes and partial failures (esp. Hungary and Turkey). And the threat and actions of Russia has in turn strengthened the need for NATO.
Edit: I stand corrected - Concrete steps were taken for Russia to join NATO.