Was Portal a buggy game to you when you played it? Did you have any real problems when you played every level, beginning to end?
More importantly, perhaps, if you did happen to encounter any major issues with Portal, were they not fixed within a week or two? Are these bugs they're fixing now, 2 and a half years after the game's release, things that have pissed you off for the last 2 and a half years?
Would you have even known that these bugs existed, having personally encountered them, or even seeing them mentioned on the internet, had Valve not published a changelist saying that they fixed it?
If you didn't encounter issues, or issues you did encounter were fixed quickly, and the issues they're currently fixing are those you didn't even know existed in the first place, why do you care?