Is there a fix for intermittent "[app name] succesfully updated" notifications?
I see what you're saying... one way around it, is to look in the logcat and keep an eye out for something like the following, in this case, I downloaded an app called Rendezvous, this is what appears in the logcat

D/PackageManager(  242): Scanning package com.jgms.rendezvous
I/PackageManager(  242): Package com.jgms.rendezvous codePath changed from /data/app/com.jgms.rendezvous-1.apk to /data/app/com.jgms.rendezvous-2.apk; Retaining data and using new
I/PackageManager(  242): Unpacking native libraries for /data/app/com.jgms.rendezvous-2.apk
D/installd(  120): DexInv: --- BEGIN '/data/app/com.jgms.rendezvous-2.apk' ---
D/dalvikvm(23670): creating instr width table
D/dalvikvm(23670): DexOpt: load 22ms, verify+opt 203ms
D/installd(  120): DexInv: --- END '/data/app/com.jgms.rendezvous-2.apk' (success) ---
D/PackageManager(  242):   Activities: com.jgms.rendezvous.login com.jgms.rendezvous.MakeWaypoint com.jgms.rendezvous.FindExisting com.jgms.rendezvous.ShareLocation com.jgms.rendezvous.FindFriend com.jgms.rendezvous.ShowMap com.jgms.rendezvous.About
I/ActivityManager(  242): Force stopping package com.jgms.rendezvous uid=10202
W/PackageManager(  242): Code path for pkg : com.jgms.rendezvous changing from /data/app/com.jgms.rendezvous-1.apk to /data/app/com.jgms.rendezvous-2.apk
W/PackageManager(  242): Resource path for pkg : com.jgms.rendezvous changing from /data/app/com.jgms.rendezvous-1.apk to /data/app/com.jgms.rendezvous-2.apk
I/installd(  120): move /data/dalvik-cache/data@app@com.jgms.rendezvous-2.apk@classes.dex -&gt; /data/dalvik-cache/data@app@com.jgms.rendezvous-2.apk@classes.dex
D/PackageManager(  242): New package installed in /data/app/com.jgms.rendezvous-2.apk


Notice the last line, "New package installed...."

If there's any other way, I'd gladly amend this :)